Co-reporter:Chun-Fai Ng, Hak-Fun Chow, Dietmar Kuck, and Thomas C. W. Mak
Crystal Growth & Design May 3, 2017 Volume 17(Issue 5) pp:2822-2822
Publication Date(Web):April 7, 2017
DOI:10.1021/acs.cgd.7b00278
Hydrogen-bond-assisted host–guest complexation of a tris(catechol)-functionalized tribenzotriquinacene with various tetraalkylammonium halides yielded diversified supramolecular architectures ranging from octameric C3-symmetric cages and C2- and C4-symmetric channels to corrugated layers, depending on both the anionic and cationic components of the guest species. Single crystal X-ray analyses of this series of complexes revealed intricate anionic host networks formed by intermolecular O–H···O and O–H···X hydrogen-bonds involving catechol host molecules and halides, which accommodate the bulky quaternary ammonium guest ions in cavities, channels, or between corrugated sheets. With fine-tuning of the symmetry and size of the hydrophobic cationic guest and accompanying halide species, this simple “Mix and Match” of host and guest components provides an efficient route to the assembly of supramolecular architectures.
Co-reporter:Yun-Peng Xie, Jun-Ling Jin, Guang-Xiong Duan, Xing Lu, Thomas C.W. Mak
Coordination Chemistry Reviews 2017 Volume 331() pp:54-72
Publication Date(Web):15 January 2017
DOI:10.1016/j.ccr.2016.10.007
•Structural features of silver sulfide/thiolate and silver thiolate clusters.•Structural features of silver selenide/selenolate clusters.•Structural features of silver tellurolate and silver telluride/tellurolate clusters.•Structural features of silver dithiophosphate/diselenophosphate clusters.•Optical and electronic properties of high nuclearity silver(I) chalcogenolate clusters.The high-nuclearity silver(I) clusters, a novel class of supramolecular assembly of silver(I) complexes, were usually prepared by incorporating silver ions with various ligands. Notably, a large number of argentophilic interactions exist in the high-nuclearity silver clusters. These interactions influence significantly a variety of structural and other physical characteristics. Thus, we will summarize the synthesis and structure of high-nuclearity silver(I) clusters with chalcogenide [E]2− (E = S, Se and Te), chalcogenolate [RE]− (E = S, Se and Te), dichalcogenophosphate [(RO)2PE2]− (E = S and Se), and dichalcogenophosphonate [R(R’O)PS2]− or [RP(O)S2]2−. This results in deeper understanding of the relationship between synthesis conditions and the finally isolated products. The literature survey is up to December 2015 and the review represents the first article covering the span of various types of high-nuclearity Ag-E clusters and should contribute considerable value for future research.
Co-reporter:Zi-Yi Chen;Dennis Y. S. Tam
Nanoscale (2009-Present) 2017 vol. 9(Issue 26) pp:8930-8937
Publication Date(Web):2017/07/06
DOI:10.1039/C7NR00931C
Using a chloride-assisted supramolecular building-block approach, we have employed the molecular Cl@Agm(CCPh)n entity in the construction of a gigantic cluster namely [Ag216S56Cl7(CCPh)98(H2O)12][Ag3(imidazole)(H2O)4](SbF6)2 (1), which contains the largest discrete organometallic cluster investigated by X-ray crystallography. Based on an icosahedral Cl@Ag12 kernel, this spheroidal cluster features an unprecedented five-shell structure Cl@Ag12@S12@Ag32@S44Cl6@Ag172 with idealized Th symmetry. The MALDI-MS, 1D, 2D 1H NMR, electronic absorption, emission spectra and HR-TEM of 1 were measured. Compound 1 shows intense red luminescence in solution at room temperature (QY = 4.7% in CH2Cl2), in addition to its 3.4 nm diameter, which makes it a unique example that fills the gap between small luminescent silver clusters and large luminescent silver nanoparticles.
Co-reporter:Leon Li-Min Zhang; Thomas C. W. Mak
Angewandte Chemie International Edition 2017 Volume 56(Issue 51) pp:16228-16232
Publication Date(Web):2017/12/18
DOI:10.1002/anie.201708760
AbstractIn the comproportionation reaction of CuIIX2 and Cu0 with isopropylacetylene (iPr−C≡C−H), the ethynediide species C22− is generated via concomitant C−H/C−C bond cleavage of the iPr−C≡C−H precursor under moderate temperature to direct the formation of CuI mixed ethynediide/isopropylethynide nanoclusters (potentially explosive). The active ethynediide dianion C22− exhibits chameleon-like templating behavior to form C2@Cum (m=6 (3, 4), 7 (2, 4), 8 (1)) central structural units for successive formation of {C22−⊂Cu24} (1, 2), {6 C22−⊂Cu48} (3), and {18 C22−⊂Cu92} (4) complexes. Bearing the highest C22− content, complex 4 features an unprecedented nanoscale Cu2C2 kernel. Furthermore, 1–3 exhibit structure-controlled photoluminescence in the solid state.
Co-reporter:Leon Li-Min Zhang; Thomas C. W. Mak
Angewandte Chemie 2017 Volume 129(Issue 51) pp:16446-16450
Publication Date(Web):2017/12/18
DOI:10.1002/ange.201708760
AbstractIn the comproportionation reaction of CuIIX2 and Cu0 with isopropylacetylene (iPr−C≡C−H), the ethynediide species C22− is generated via concomitant C−H/C−C bond cleavage of the iPr−C≡C−H precursor under moderate temperature to direct the formation of CuI mixed ethynediide/isopropylethynide nanoclusters (potentially explosive). The active ethynediide dianion C22− exhibits chameleon-like templating behavior to form C2@Cum (m=6 (3, 4), 7 (2, 4), 8 (1)) central structural units for successive formation of {C22−⊂Cu24} (1, 2), {6 C22−⊂Cu48} (3), and {18 C22−⊂Cu92} (4) complexes. Bearing the highest C22− content, complex 4 features an unprecedented nanoscale Cu2C2 kernel. Furthermore, 1–3 exhibit structure-controlled photoluminescence in the solid state.
Co-reporter:Sam C. K. Hau
Dalton Transactions 2017 vol. 46(Issue 41) pp:14098-14101
Publication Date(Web):2017/10/24
DOI:10.1039/C7DT03406G
New tetranuclear supramolecular precursors [(R–CC–CC)Ag(PPh3)]4 (R = iPr and chx) are employed to construct three polynuclear silver(I) alkyl-1,3-diynyl cluster complexes (1–3) that bear the same novel trigonal bipyramidal Ag5 core consolidated by silver–ethynide and argentophilic interactions. The present results strongly suggest that the assembly of high-symmetry medium-nuclearity clusters 1–3 is initiated by the accretion of additional Ag(I) ions by the Ag4 template of the precursors through argentophilic (<3.4 Å) interaction, and demonstrate that core transformation is an effective synthetic route to high-symmetry metal clusters.
Co-reporter:Sam C. K. Hau, Margaret C.-L. Yeung, Vivian W.-W. Yam, and Thomas C. W. Mak
Journal of the American Chemical Society 2016 Volume 138(Issue 41) pp:13732-13739
Publication Date(Web):September 27, 2016
DOI:10.1021/jacs.6b08674
New tetranuclear supramolecular precursors [(R—C≡C—C≡C)Ag]4 (R = iPr, tBu, and chx) are employed to construct a series of heterometallic silver(I)–copper(I) alkyl-1,3-diynyl cluster complexes (1–9) that bear a common CuAg3 core (normally trigonal-planar, but can be distorted to pyramidal) consolidated by cupro-argentophilic interaction under 3.12 Å, as found in 1 and 2. The photophysical properties of the multinuclear supramolecular precursors and selected complexes have been investigated. The present results strongly suggest that the assembly of medium-nuclearity clusters 3 to 9 is initiated by accretion of additional Ag(I) ions by the ubiquitous CuAg3 template through argentophilic (<3.4 Å) interaction, with cooperative cuprophilic enhancement (<2.76 Å) in the case of compound 9. To our knowledge, the present study provides the first report of conversion of a Group 11 homonuclear cluster into a heteronuclear one of higher nuclearity via inner-core expansion.
Co-reporter:Li-Min Zhang
Journal of the American Chemical Society 2016 Volume 138(Issue 9) pp:2909-2912
Publication Date(Web):February 20, 2016
DOI:10.1021/jacs.5b12103
Comproportionation reaction of Cu(II) salt and copper metallic powder in the presence of tert-butylacetylene (tBuC≡CH) in methanol at room temperature yielded discrete Cu(I) tert-butylethynide clusters whose identity depended on the particular co-existing anion employed. Introduction of polyoxomolybdate to the reaction system afforded two new core–shell nanoclusters, [Cu33(tBuC≡C)24(Mo4O16)]·BF4 (3) and [Cu62(tBuC≡C)34(Mo5O19)2(MoO4)2(OTf)2(OH)4]·(OTf)2 (4). Complexes 3 and 4 represent the first examples of high-nuclearity Cu(I) clusters that encapsulate polyoxometalate templates, and the latter features the largest Cu(I) alkynyl cluster known to date. The present study not only demonstrates a new paradigm for the designed synthesis of Cu(I) alkynyl clusters but also opens the door to understanding Cu(I) alkynyl structural chemistry.
Co-reporter:Zi-Yi Chen, Dennis Y. S. Tam and Thomas C. W. Mak
Chemical Communications 2016 vol. 52(Issue 36) pp:6119-6122
Publication Date(Web):06 Apr 2016
DOI:10.1039/C6CC02631A
Inexpensive 1,1′-thiocarbonyldiimidazole and di(2-pyridyl) thionocarbonate have been used as respective sulfide precursors to assemble unprecedented high-nuclearity ethynide-stabilized silver(I) sulfido molecular clusters [Ag9S6@Ag36(CCtBu)32(H2O)2] [Ag(imidazole)(CH3OH)(H2O)](BF4)2·8H2O·2CH3OH (1) and [Ag120S24(PhCC)52Cl4(2-pyridone)10(H2O)8](H3O)4(SiF6)8(BF4)4·CH3OH·22H2O (2), the latter being the largest isolated silver(I) ethynide cluster reported to date.
Co-reporter:Xue Han, Shan-Shan Jin, Jian-Fang Ma, Jin Yang, and Thomas C. W. Mak
Crystal Growth & Design 2016 Volume 16(Issue 7) pp:3811-3817
Publication Date(Web):May 26, 2016
DOI:10.1021/acs.cgd.6b00364
We present a new family of Ag(I) complexes bearing calixarene-based tetraethynide ligands, namely, [Ag12(L1)2·(CH3CN)4·(NO3)4]·2H2O (1), [Ag4L1·(AgCF3CO2)4·(CH3OH)] (2), [Ag4L2·(AgCF3CO2)4]·H2O (3), and [Ag4L3·(AgCF3CO2)4]·0.75CH3COCH3 (4), which were obtained from the reaction of newly synthesized tetraethynyl functionalized resorcin[4]arenes with silver(I) salts. Complex 1 features a 4/m assembly comprising a Ag12 cage sandwiched by two bowl-shaped resorcin[4]arene tetraethynides, while 2–4 exhibit similar silver(I) chain structures each stabilized by an alternate attachment of bowl-shaped resorcin[4]arene tetraethynide units. This work provides the successful example of the use of calixarene-based ligands for the construction of multinuclear silver(I)–ethynide supramolecular frameworks.
Co-reporter:Sam C. K. Hau
Journal of the American Chemical Society 2014 Volume 136(Issue 3) pp:902-905
Publication Date(Web):January 3, 2014
DOI:10.1021/ja412095y
Two new silver(I) carbides, Ag2C6 and Ag2C8, have been synthesized, and single-crystal X-ray analysis of their crystalline silver(I) trifluoroacetate complexes, Ag2C6·8AgCF3CO2·6H2O, 4(Ag2C6)·16AgCF3CO2·14.5DMSO, and 2.5(Ag2C8)·10AgCF3CO2·10DMSO, provides detailed information on the influence of ligand disposition and orientation of the all-carbon anionic ligands in the construction of multidimensional supramolecular structures, which are consolidated by argentophilic and weak inter-/intramolecular interactions.
Co-reporter:Jin Yang, Ting Hu, and Thomas C. W. Mak
Crystal Growth & Design 2014 Volume 14(Issue 6) pp:2990-3001
Publication Date(Web):May 1, 2014
DOI:10.1021/cg500271f
A new family of 10 organosilver(I) complexes, namely, [(AgC≡CPh)2(AgO2CCF3)4(cis-1,2-bix)(CH3OH)]·2CH3OH (1,2-bix = 1,2-bis(imidazol-1-ylmethyl)benzene, 1A), [(AgC≡CC6H4Me-2)2(AgO2CCF3)4(cis-1,3-bix)]·5.25H2O (1,3-bix = 1,3-bis(imidazol-1-ylmethyl)benzene, 1B), [(AgC≡CPh)3(AgO2CCF3)6(trans-1,4-bix)(CH3OH)3]·2CH3OH (1,4-bix = 1,4-bis(imidazol-1-ylmethyl)benzene, 2A), [(AgC≡CC6H4Me-4)3(AgO2CCF3)6(trans-1,4-bix)(CH3OH)3]·2CH3OH (2B), [(AgC≡CPh)(AgO2CCF3)3(trans-1,3-bix)(H2O)]·0.5H2O (3A), [(AgC≡CC6H4Me-4)(AgO2CCF3)3(trans-1,3-bix)(H2O)] (3B), [(AgC≡CC6H4Me-4)(AgO2CCF3)3(bbi)(H2O)] (bbi = 1,1′-(1,4-butanediyl)bis(imidazole), 3C), [(AgC≡CC6H4tBu-4)(AgO2CCF3)3(trans-1,4-bix)] (3D), [(AgC≡CPh)2(AgO2CCF3)4(bbi)(H2O)]·2H2O (4), and [(AgC≡CtBu)2(AgO2CCF3)4(bbi)] (5), have been synthesized employing a variable combination of ethynide, trifluoroacetate, and bridging bis(imidazole) ligands. In both 1A and 1B, the flexible 1,2-bix or 1,3-bix ligands in cis-conformations are alternatively attached on both sides of an infinite cationic silver(I) chain, and neighboring organosilver(I) chains are further interconnected by intermolecular hydrogen bonds to generate a three-dimensional supramolecular architecture. In structural analogues 2A and 2B, pairs of silver(I) chains are linked via the trans-1,4-bix ligands to yield infinite ladders, which are further joined together by hydrogen bonds to afford a three-dimensional supramolecular network. In the isostructural series 3A–3D, centrosymmetric (PhC2)2Ag8 aggregates are connected by trifluoroacetate groups to give an infinite chain, and such chains are then bridged by bis(imidazole) ligands to generate a coordination layer. Furthermore, adjacent layers are linked by hydrogen bonds to form a three-dimensional supramolecular network. In 4, infinite silver(I)–phenylethynide chains constructed by Ag6 aggregates are bridged by bbi ligands in a gauche–trans–gauche conformation to yield a three-dimensional coordination framework. In contrast, infinite silver(I)-tert-butylethynide chains based on Ag8 and Ag6 aggregates in 5 are linked by bbi ligands exhibiting different trans–trans–trans and gauche–trans–gauche conformations to generate a three-dimensional coordination network. Finally, the roles played by various bis(imidazole) ligands and ethynides bearing different substituents in the framework assembly are discussed in detail.
Co-reporter:Sam C. K. Hau and Thomas C. W. Mak
Crystal Growth & Design 2014 Volume 14(Issue 7) pp:3567-3575
Publication Date(Web):May 14, 2014
DOI:10.1021/cg5004963
Single-crystal X-ray analysis of a series of six silver(I) trifluoroacetate complexes containing designed ligands each composed of a functionalized cis- or trans-stilbene skeleton bearing two terminal ethynyl groups at variable ring positions provided detailed information on the influence of ligand disposition and orientation, coordination preferences, and coexistence of different types of silver(I)–carbon bonding (silver–ethynide, silver–ethenyl and silver–aromatic) in the construction of a coordination network, which are consolidated by argentophilic and weak intra/intermolecular interactions. The complex 3(Ag2L6)·14AgCF3CO2·[Ag2(CH3CN)3](CF3CO2)2·4H2O·6CH3CN [H2L6 = (E)-1,2-bis(4-ethynylphenyl)ethene] is the first reported example in which an ethynide terminal is bound by six silver(I) ions.
Co-reporter:Han Wang, Chong-Qing Wan, Jin Yang, and Thomas C. W. Mak
Crystal Growth & Design 2014 Volume 14(Issue 7) pp:3530-3540
Publication Date(Web):May 26, 2014
DOI:10.1021/cg500474j
Seven new Ag(I) complexes based on conformationally flexible 2,6-bis(pyrazin-2-ylthio)pyrazine (L) and selected carboxylate ligands, Ag2(L)2(L1)2 (1), [Ag(L)(L2)]∞ (2), [Ag2(L)(L3)2]∞ (3), [Ag2(L)(L4)2]∞ (4), {[Ag2(L)(L5)]·4H2O}∞ (5), {[Ag2(L)(L6)]·3H2O}∞ (6), and {[Ag2(L)2(L7)]·3H2O}∞ (7) (L1 = trifluoroacetate, L2 = heptafluorobutanoate, L3 = 4-cyanobenzoate, L4 = 2-(perfluorophenoxy)acetate, L5 = 1,1′-biphenyl-4,4′-dicarboxylate, L6 = 2,2′-(1,4-phenylene)diacetate, and L7 = naphthalene-2,6-dicarboxylate), have been synthesized and structurally characterized by single-crystal X-ray diffraction analyses. In 1–7, an argentophilic Ag2 dimer was found to be a dominant subunit, which is stabilized by a pair of bridging carboxylate groups. Complexes 1–4 are assembled with monocarboxylates, L, and Ag(I) ions. Complex 1 exists as a discrete dimeric molecule, being stabilized by trans pairs of L and L1. Co-crystallization of discrete molecules and infinite chains occur in complex 2. In 3 and 4, Ag2 dimers are linked by ligands L to furnish a double-bridged chain and a ladder-like structure, respectively. Complexes 5–7 are assembled with dicarboxylate spacers and flexible L, which link Ag2 units to form a 2D slablike architecture in 5, and 3D coordination frameworks in 6 and 7. In addition, the effect of the carboxylate ligands on the ligation behavior of L and supramolecular assembly of the series of compounds are discussed in detail.
Co-reporter:Han Wang, Chong-Qing Wan and Thomas C. W. Mak
Dalton Transactions 2014 vol. 43(Issue 19) pp:7254-7262
Publication Date(Web):06 Mar 2014
DOI:10.1039/C3DT53344A
Two novel coordination polymers [Ag16(SO4)8][Ag4(SO4)2]3(L1)12·nH2O (n = 72) (1) and [Ag10(SO4)5(L2)4(H2O)2]·8H2O (2) based on conformationally variable oligo-α-heteroarylsulfanyl ligands 2-(pyrazin-2-ylthio)-6-(pyridin-2-ylthio)pyrazine (L1) or 2,6-bis(pyrazin-2-ylthio)pyrazine (L2) and sulfate-templated high-nuclearity Ag(I) clusters as structure-building units (SBUs) have been synthesized under mild conditions. Single-crystal X-ray analysis showed that complex 1 exhibits a porous three-dimensional framework containing Ag16(SO4)8 and Ag4(SO4)2 SBUs that are interconnected by L1 ligands, whereas 2 has a much denser network constructed from Ag10(SO4)5 SBUs and L2 linkers. To our knowledge, the Ag16(SO4)8 cluster core found in 1 is the largest sulfate-based polynuclear SBU in coordination polymers, and the 14-connected Ag10(SO4)5 in 2 is the highest-connectivity Ag(I) cluster SBU reported to date. These two complexes were fully characterized by infrared spectroscopy, elemental analysis, powder X-ray diffraction, thermogravimetric analysis and differential scanning calorimetry.
Co-reporter:Ting Hu, Jin Yang and Thomas C. W. Mak
CrystEngComm 2014 vol. 16(Issue 28) pp:6316-6324
Publication Date(Web):18 Nov 2013
DOI:10.1039/C3CE41671B
Six new silver ethynediide complexes containing trifluoroacetate and ligands derived from isomeric dicyanobenzenes, namely 2Ag2C2·10AgCF3CO2·3L1 (L1 = 1,2-dicyanobenzene) (1), 2Ag2C2·10AgCF3CO2·AgNO3·4L2 (L2 = 1,3-dicyanobenzene) (2), Ag2C2·2AgCF3CO2·2AgL3H·H2O (L3H2 = benzene-1,3-dicarboxylic acid) (3), Ag2C2·2AgCF3CO2·AgL3H·AgL4 (L4H = 3-cyanobenzenecarboxylic acid) (4), Ag2C2·4AgCF3CO2·2AgL5·4H2O (L5H = 4-cyanobenzenecarboxylic acid) (5) and 2Ag2C2·6AgCF3CO2·4AgL5·Ag2L6 (L6H2 = benzene-1,4-dicarboxylic acid) (6), have been synthesized under hydrothermal conditions and characterized using single crystal X-ray analysis. The Ln (n = 1–6) ligands incorporated into the silver ethynediide reaction system were generated in situ from hydrolysis of the o-, m- or p-isomers of dicyanobenzene. In the crystal structures of compounds 1–6, there are various types of silver(I) cages each enclosing a C22− dianion, which can be regarded as a multinuclear metal–ligand supramolecular synthon and symbolized as C2@Agn (n = 6–8). The silver cages are fused into infinite silver chains, which are connected by dicyanobenzene derivatives to yield two- and three-dimensional coordination networks in 1 and 2–6, respectively. The coordination capacity and structure-directing effect of the Ln ligands, as well as the temperature and pH value of the reaction mixture on the crystal structure of the resulting products, were also investigated.
Co-reporter:Han Wang, Jin Yang and Thomas C. W. Mak
New Journal of Chemistry 2014 vol. 38(Issue 10) pp:4690-4695
Publication Date(Web):26 Jun 2014
DOI:10.1039/C4NJ00836G
Three genuine supramolecular isomers and one homologous complex based on a conformationally flexible multidentate 2,6-bis(pyrazin-2-ylthio)pyrazine (L) ligand, namely α-[Ag(L)ClO4]n (1a), β-[Ag(L)ClO4]n (1b), γ-[Ag(L)ClO4]n (1c) and [Ag2(L)3(ClO4)2·2H2O]n (2), have been synthesized and structurally characterized by single-crystal X-ray diffraction analyses. Isomers 1a–1c feature a chain, a sheet and a three-dimensional framework, respectively. Compound 2 shows a ladder-like structure with an unusual zigzag water chain. In these complexes, ligand L exhibits four distinct coordination modes and stereochemical conformations, and their effects on the formation of supramolecular isomers are discussed in detail.
Co-reporter:Sam C. K. Hau, Ping-Shing Cheng, and Thomas C. W. Mak
Organometallics 2014 Volume 33(Issue 13) pp:3231-3234
Publication Date(Web):June 26, 2014
DOI:10.1021/om5003733
The multinuclear metal–ligand supramolecular synthon RC6H4C≡C⊃Agn (R = Me, F; n = 3–5) has been employed to construct the two high-nuclearity silver ethynide cluster compounds [(NO3)2@Ag26(o-MeC6H4C≡C)16](NO3)8·5H2O (1) and [NO3@Ag15(o-FC6H4C≡C)10](NO3)4 (2), which bear the same nitrate central core. The synthesis of [CrO4@Ag18(iPrC≡C)12](ClO4)4 (3) and [ClO4@Ag18(iPrC≡C)12](ClO4)5 (4) demonstrated the effect of variation of central anionic core size and charge on the construction of multidimensional organosilver(I) networks. The bulkiness of the peripheral ligands and the orientation of substituents with respect to the ethynide group proved to be dominant factors that direct the formation of high-nuclearity clusters and the assembly of coordination networks. To our knowledge, 1 and 2 are the first examples using the nitrate anion for templated cluster synthesis.
Co-reporter:Sam C. K. Hau;Dennis Y. S. Tam
Acta Crystallographica Section B 2014 Volume 70( Issue 1) pp:37-46
Publication Date(Web):
DOI:10.1107/S2052520614000171
Eight new silver(I) trifluoroacetate complexes based on a series of designed ligands, each featuring an alicyclic ring with enediyne functionality, have been synthesized and characterized by single-crystal X-ray diffraction. Each ethynide terminal is inserted into an Agn (n = 4–5) basket, leading to the generation of coordination chain or layer structures, but the well shielded ethenyl group does not take part in silver-olefin bonding. Variation in ring size of the alicycles is shown to influence the construction of the organosilver(I) coordination networks, which are consolidated by weak intermolecular interactions in the crystal structures. The effect of adding ancillary N-donor ligands to the reaction system on the coordination and supramolecular network assembly is also investigated.
Co-reporter:Yun-Peng Xie
Journal of Cluster Science 2014 Volume 25( Issue 1) pp:189-204
Publication Date(Web):2014 January
DOI:10.1007/s10876-013-0651-7
A large family of crystalline organometallic compounds with silver ethynide (R–C≡CAg) as a component has been synthesized and characterized. In most cases the R–C≡C− species coordinate to 3–5 silver(I) atoms, which may be symbolized as R–C≡C⊃Agn (n = 3, 4, 5; R = alkyl, aryl, heteroaryl) by leaving out the charges. In the present review, emphasis is laid on systematic synthetic and structural studies of high-nuclearity silver ethynide clusters, of which the size and shape can be controlled to a certain extent by the judicious choice of templating anions and auxiliary ligands.
Co-reporter:Xi-Yan Dong ; Bo Li ; Bin-Bin Ma ; Shi-Jun Li ; Ming-Ming Dong ; Yan-Yan Zhu ; Shuang-Quan Zang ; You Song ; Hong-Wei Hou ;Thomas. C. W. Mak
Journal of the American Chemical Society 2013 Volume 135(Issue 28) pp:10214-10217
Publication Date(Web):July 5, 2013
DOI:10.1021/ja403449k
A polar homochiral 3D MOF [{Co2(L)(bpe)(H2O)}·5H2O]n constructed with cobalt(II) and a new ligand N-(1,3-dicarboxy-5-benzyl)-carboxymethylglycine (H4L) accommodates ordered helical water streams in its helical grooves. It provides the first example of switchable ferroelectric and optical behavior through two-step reversible single-crystal to single-crystal transformation (SCSC) upon desorption/adsorption of water spirals and coordinated water molecules, respectively.
Co-reporter:Ting Hu and Thomas C. W. Mak
Inorganic Chemistry 2013 Volume 52(Issue 15) pp:9066-9076
Publication Date(Web):July 25, 2013
DOI:10.1021/ic401259r
A series of seven new silver(I) multiple salts containing C22– (ethynediide, acetylenediide), phosphonate, and perfluorocarboxylate ligands, Ag2C2·2AgCF3CO2·2Ag2PhPO3·Ag3[(PhPO3)2H] (1), 4Ag2C2·4AgCF3CO2·6Ag2PhPO3·2AgPhPO3H·3H2O (2), Ag2C2·2AgCF3CO2·Ag2PhPO3·3AgPhPO3H (3), Ag2C2·AgCF3CO2·Ag2tBuPO3·2AgtBuPO3H (4), Ag2C2·AgCF3CO2·2Ag2tBuPO3 (5), 2Ag2C2·2AgC2F5CO2·4Ag2PhPO3·H2O (6), and 1.5Ag2C2·6AgC2F5CO2·Ag2PhCH2PO3·AgPhCH2PO3H·6H2O (7), have been synthesized under hydrothermal conditions by varying the types of phosphonic and perfluorocarboxylic acid employed, as well as the mole ratios of the reactants. In compound 1, C2@Ag9 building units (each with a C22– species located inside a Ag9 monocapped distorted square antiprism) are consolidated by trifluoroacetate ligands and interconnected by phenylphosphonate groups to form a two-dimensional coordination network. Compound 2 is composed of two kinds of C2@Ag6 silver cages that are fused together to form an argentophilic chain; such chains are in turn further linked by the phenylphosphonate ligands into a two-dimensional network. Compound 3 also has a layer structure, whose core is a centrosymmetric (C2)2@Ag18 aggregate. In compound 4, centrosymmetric (C2)2@Ag14 aggregates are cross-linked into a coordination layer, and such layers are further assembled into a three-dimensional supramolecular architecture via hydrogen bonding. Compound 5 has an argentophilic layer structure generated from the fusion and linkage of C2@Ag8 cages. Compound 6 exhibits an argentophilic layer structure in which the basic building unit is an unusual silver(I) aggregate composed of four different kinds of C2@Ag6 cages. The crystal structure of compound 7 is a three-dimensional coordination network, in which the coordination chains containing two kinds of C2@Ag8 single cages are bridged by aqua ligands.
Co-reporter:Chong-Qing Wan, Ai-Min Li, Shaeel A. Al-Thabaiti, and Thomas C. W. Mak
Crystal Growth & Design 2013 Volume 13(Issue 5) pp:1926-1936
Publication Date(Web):March 20, 2013
DOI:10.1021/cg3017408
In a series of nine group 12 metal complexes of 2,6-pyridinediylbis(3-pyridinyl)methanone (abbreviated as L), namely, [Cd(L)2Cl2] (1), [Cd(L)2(NO3)2]·3.5H2O (2), [Cd(L)2(H2O)2](NO3)2 (3), [Cd(L)2(H2O)2](ClO4)2·H2O (4), {[Cd(L)(H2O)2](ClO4)2·1.5H2O}∞ (5), {[Cd(L)2SO4(H2O)]·2.8H2O}∞ (6), [Cd(L)2(CH3CO2)2]∞ (7), [Zn(L)2(CH3CO2)2]∞(8), and [Hg(L)2(CH3CO2)2]∞ (9), the semirigid multidentate ligand L exhibits flexible ligation modes I–IV in response to the cooperative effect of counteranions and solvent medium, leading to mononuclear (1–4), helical-chain (6), zigzag-chain (7), and 3D net (5) coordination motifs. The presence of the ancillary aqua ligand is essential for the crystallization of 3 and 5 by addition of deionized water to an organic mixed-solvent medium containing 2 and 4, respectively. The acetate complexes 7 (Cd2+), 8 (Zn2+), and 9 (Hg2+) are isostructural. Unconventional anion−π(pyridine), C═O···C═O, O(NO3–/ClO4–)···C═O, and cohesive nitrate···nitrate interactions are manifested in supramolcular aggregations of the present series of crystalline complexes.
Co-reporter:Ting Hu and Thomas C. W. Mak
Crystal Growth & Design 2013 Volume 13(Issue 11) pp:4957-4967
Publication Date(Web):September 4, 2013
DOI:10.1021/cg401150t
Seven new silver ethynediide complexes containing ancillary heteroaromatic N-donor ligands, namely, Ag2C2·4AgCF3CO2·(bipyH)(CF3CO2)·H2O (1), Ag2C2·7AgCF3CO2·(H3O)(CF3CO2)·2(bipyH2)(CF3CO2)2·3H2O (2), 2Ag2C2·8AgCF3CO2·6L1 (L1 = pyrazole) (3), Ag2C2·4AgCF3CO2·2L2 (L2 = 3,5-dimethylpyrazole) (4), Ag2C2·4AgCF3CO2·2L3 (L3 = 1,2,4-triazole) (5), Ag2C2·10AgCF3CO2·2L4 (L4 = 4,5-dihydro-3-(4-pyridinyl)-2H-benz(g)-indazole) (6), and Ag2C2·5AgCF3CO2·2(H3O)(CF3CO2)·3(AgL52)(CF3CO2)·2(L5H)(CF3CO2)·2(H2O) (L5 = benzimidazole) (7) have been synthesized under hydrothermal conditions and characterized by single crystal X-ray analysis. Directed by N-donor ligands of different bulkiness and disposition of coordinating sites, various silver chain-type architectures (compounds 1 and 3–6) and discrete molecular structures (2 and 7) were assembled. In the case of 1 and 2, the influence of nonincorporated additive agents (NH4)2HPO4 and H2C2O4·H2O on product formation was also investigated.
Co-reporter:Yun-Peng Xie and Thomas C. W. Mak
Dalton Transactions 2013 vol. 42(Issue 36) pp:12869-12872
Publication Date(Web):23 Jul 2013
DOI:10.1039/C3DT51461G
Three new silver(I) phosphonate complexes have been synthesized from silver phenylethynide as a structure-directing precursor. Ag2(PhPO3)(H2O) displays a layer-type coordination network, Ag(3,5-dimethylpyrazole)2(PhPO3H) contains a dimeric unit, and {Ag8(dppm)4(tBuPO3)2(ClO4)(NO3)0.67(H2O)1.33}·(ClO4)2.33·(CH3OH)6.67 features an octanuclear composite cluster. We have also isolated the pyrophenylphosphonate complex Ag2[PhPO2(O)O2PPh](CH3CN), which exhibits an infinite-chain structure.
Co-reporter:Chong-Qing Wan;Shaeel A. Al-Thabaiti;Xu-Dong Chen
European Journal of Inorganic Chemistry 2013 Volume 2013( Issue 30) pp:5265-5273
Publication Date(Web):
DOI:10.1002/ejic.201300696
Abstract
The reaction of 2,6-pyridinediylbis(3-pyridinyl)methanone (abbreviated as L) with various silver(I) salts yielded a series of complexes, namely, [Ag2(L)2](ClO4)2 (1), {[Ag2(L)2](ClO4)2}∞ (2), {[Ag2(L)2](NO3)2}∞ (3), {[Ag2(L)2](C2F5CO2)2}∞ (4), {[Ag2(L)2](C3F7CO2)2}∞ (5), and {[Ag2(L)2](O2CC3F6CO2)·2H2O}∞ (6), which exhibit a common dinuclear metallacyclic [Ag2(L)2]2+ skeleton that involves linear-dicoordinate AgI and μ2-N,N-bridging L. Complex 2 is a polymorph of 1 obtained by the solvent-medium tuning effect, and it has an {[Ag2(L)2]2+}∞ infinite-chain structure. In complexes 3–6, the argentophilic interaction plays an important role in connecting the [Ag2(L)2]2+ units to form a similar {[Ag2(L)2]2+}∞ chain structure to that in 2, although the counteranions are markedly different. The copper(II) complex {[Cu2(CH3CO2)4(L)]·2H2O}∞ (7) exhibits a zigzag-chain structure composed of an alternating arrangement of L and the Cu2(CH3CO2)4 paddlewheel cluster. In the supramolecular architectures of 1–7, the counteranions engage in multiple noncovalent interactions, and the presence of unusual types such as O/F(anion)···π, O/F(anion)···C=O, and C=O···π are noted and discussed.
Co-reporter:Ting Hu
European Journal of Inorganic Chemistry 2013 Volume 2013( Issue 31) pp:5476-5486
Publication Date(Web):
DOI:10.1002/ejic.201300798
Abstract
Ten new silver(I) trifluoroacetate complexes containing the 1,5-hexadiyne-1,6-diide dianion and various types of ancillary heteroaromatic N-donor ligands, namely, Ag2C6H4·5AgCF3CO2·4H2O (1), Ag2C6H4·5AgCF3CO2·3L1 (L1 = imidazole) (2), 3Ag2C6H4·10AgCF3CO2·4L2 (L2 = pyrazole, 3), Ag2C6H4·AgCF3CO2·5L3·H2O (L3 = 3,5-dimethylpyrazole, 4), Ag2C6H4·5AgCF3CO2·2L4 (L4 = 2,2′-bipyridine, 5), Ag2C6H4·3AgCF3CO2·L5 [L5 = trans-1,2-di(4-pyridyl)ethylene, 6], Ag2C6H4·4AgCF3CO2·L6 (L6 = 1,4-dicyanobenzene, 7), Ag2C6H4·6AgCF3CO2·2AgL7·H2O (HL7 = 4-pyridinecarboxylic acid, 8), Ag2C6H4·3AgCF3CO2·2AgL8 (HL8 = pyrazine-2-carboxylic acid, 9), and Ag2C6H4·3AgCF3CO2·2AgL9·H2O (HL9 = 4-cyanobenzencarboxylic acid, 10) have been synthesized and characterized by single-crystal X-ray analysis. All complexes are based on assemblies with the multinuclear metal–ligand supramolecular synthon C6H4⊂Agn (n = 7, 8, 9), in which the C6H42– ligand has a gauche configuration. Complexes 2, 4, and 5 each possess an infinite argentophilic silver(I) chain coordinated by N-donor ligands, and such coordination chains are further interlinked into a three-dimensional supramolecular architecture through hydrogen bonding. Complexes 1, 3, and 7 exhibit coordination layers, which are further connected into three-dimensional supramolecular frameworks through hydrogen bonding (1 and 3) or π···π stacking interactions (7). Complexes 6, 8, 9, and 10 all have a three-dimensional coordination network with ancillary N-donor ligands as bridge linkers.
Co-reporter:Ping-Shing Cheng, Sam C.K. Hau, Thomas C.W. Mak
Inorganica Chimica Acta 2013 Volume 403() pp:110-119
Publication Date(Web):1 July 2013
DOI:10.1016/j.ica.2013.03.014
•Silver(I) nitrate complexes of aromatic ligands bearing ethynyl and isocyano substituents.•Layer-type organosilver network assembled with multinuclear supramolecular synthon R–CC⊃⊃Agn.•Influence of disposition of ethynide and isocyano groups on network construction.•Consolidation of organosilver networks by argentophilic, π–π stacking and H-bond interactions.A series of seven silver(I) nitrate complexes containing new ligands each composed of a functionalized phenyl nucleus bearing a terminal ethynyl substituent has been synthesized and characterized by single-crystal X-ray analysis. The coordination preferences of the ethynide ligand with respect to the cyano-substituent at variable positions proved to be dominant factors in directing the construction of multi-dimensional organosilver(I) networks, which are consolidated by weak intermolecular interactions in supramolecular assembly.A series of seven silver(I) nitrate complexes containing new ligands (HL1–HL7) each composed of a functionalized phenyl nucleus bearing a terminal ethynyl substituent has been synthesized and characterized by single-crystal X-ray analysis. The coordination preferences of the ethynide ligand with respect to the cyano-substituent at variable positions proved to be dominant factors in directing the construction of multi-dimensional organosilver(I) networks, which are consolidated by weak intermolecular interactions in supramolecular assembly.
Co-reporter:Yun-Peng Xie, Shaeel A. Al-Thabaiti, Mohamed Mokhtar, Thomas C.W. Mak
Inorganic Chemistry Communications 2013 Volume 31() pp:54-57
Publication Date(Web):May 2013
DOI:10.1016/j.inoche.2013.02.019
•New silver(I)–ethynide complex featuring an infinite coordination polymeric chain•Ag14(CCtBu)8(CF3CO2)24 + cluster segments bridged by two different carboxylates•Versatile supramolecular synthon RCC ⊃ Agn for synthesis of organosilver complexesFrom the reaction of AgCCtBu with 9-hydroxy-9-fluorenecarboxylic acid (HL) and AgCF3CO2, we have isolated a new type of organosilver(I) coordination polymeric chain, namely {[Ag14(CCtBu)8(L)2(CF3CO2)4]·2CH3OH}n, which contains centrosymmetric [Ag14(CCtBu)8(CF3CO2)2]4 + cluster segments bridged by pairs of L and trifluoroacetate ligands.The crystalline silver(I)–ethynide complex {[Ag14(CCtBu)8(L)2(CF3CO2)4]·2CH3OH}n (HL = 9-hydroxy-9-fluorenecarboxylic acid) is composed of a packing of organosilver(I) coordination polymeric chains each containing centrosymmetric, bar-like [Ag14(CCtBu)8(CF3CO2)2]4 + cluster segments bridged by pairs of L and trifluoroacetate ligands.
Co-reporter:Yun-Peng Xie, Shaeel A. Al-Thabaiti, Thomas C.W. Mak
Journal of Molecular Structure 2013 Volume 1048() pp:121-123
Publication Date(Web):24 September 2013
DOI:10.1016/j.molstruc.2013.05.028
•Versatile supramolecular synthon RCC⊃Agn for synthesis of silver ethynide clusters.•Novel cationic Ag24 cluster encapsulating a hexafluorosilicate template anion.•Anion-templated synthesis involving in situ generation of hexafluorosilicate.A novel high-nuclearity silver(I) ethynide cluster complex, namely {SiF6@Ag24(CCtBu)20}·SiF6, has been isolated from the reaction between AgBF4 and tBuCCAg in a glass beaker. Single-crystal X-ray analysis showed that an in situ generated hexafluorosilicate template anion occupies the central cavity of the cationic polyhedral Ag24 cluster, which is consolidated by peripheral tert-butyl ethynide groups and inter-cluster hexafluorosilicate ions.The high-nuclearity silver(I) ethynide complex, {SiF6@Ag24(CCtBu)20}·SiF6, features a polyhedral Ag24 cluster core with its central cavity occupied by a hexafluorosilicate template ion.
Co-reporter:Sam C.K. Hau, Thomas C.W. Mak
Polyhedron 2013 64() pp: 63-72
Publication Date(Web):
DOI:10.1016/j.poly.2013.02.020
Co-reporter:Ting Hu and Thomas C. W. Mak
Organometallics 2013 Volume 32(Issue 1) pp:202-208
Publication Date(Web):December 19, 2012
DOI:10.1021/om300988r
Five new silver(I) double and triple salts containing conformationally flexible 1,5-hexadiyne-1,6-diide (−C≡CCH2CH2C≡C–, C6H42–) and nitrate ions, namely Ag2C6H4·7AgNO3 (1), Ag2C6H4·3AgNO3·2AgF (2), Ag2C6H4·4AgNO3·2L1 (3; L1 = imidazole), Ag2C6H4·2AgNO3·2AgL2 (4; HL2 = pyrazole), and Ag2C6H4·4AgNO3·2L3 (5; L3 = 3,5-dimethylpyrazole), have been synthesized, in which the C6H42– species was found to adopt two distinct configurations: anti in 1 and 3 and gauche in 2, 4, and 5. Complex 1 features an unusual Ag5⊂C6H4⊃Ag4 aggregate as the basic building unit, and such aggregates are interconnected by the nitrate ions to generate a three-dimensional coordination network. Complex 2 exhibits a three-dimensional coordination network constructed with compact C6H4⊃Ag7 units, nitrate ions, and fluoride ions that assume a μ3 trigonal-pyramidal coordination mode. In 3, the Ag4⊂C6H4⊃Ag4 aggregates are stabilized by nitrate groups and imidazole ligands to generate a layer structure. In complex 4, infinite chains each bearing deprotonated pyrazole ligands attached to the silver backbone are weaved by nitrate groups to form a three-dimensional coordination architecture. In 5 the 3,5-dimethylpyrazole ligands coordinate to silver atoms at the upper surface of each coordination layer, and the layers are interconnected to form a three-dimensional supramolecular network via hydrogen bonding.
Co-reporter:Li-Li Wen, Han Wang, Chong-Qing Wan, and Thomas C. W. Mak
Organometallics 2013 Volume 32(Issue 18) pp:5144-5152
Publication Date(Web):September 9, 2013
DOI:10.1021/om400706d
Five new silver(I)–organic frameworks containing ethynediide or alkyl and aryl ethynide, together with newly designed oligo-α-sulfanylpyrazinyl ligands, namely, [(Ag2C2)2(AgCF3COO)11(L1)(μ2-DMSO)3(DMSO)5]·1/4H2O (L1 = 2,6-bis(pyridin-2-ylthio)pyrazine, 1), [(Ag2C2)2(AgCF3COO)11(L2)(μ2-DMSO)5(DMSO)3]·1/4H2O (L2 = 2-(pyrazin-2-ylthio)-6-(pyridin-2-ylthio)pyrazine, 2), [(AgC≡CtBu)2(AgCF3COO)5(L3)(DMSO)3(H2O)] (L3 = 2,6-bis(pyrazin-2-ylthio)pyrazine, 3), [(AgC≡CPh)4(AgCF3COO)2(L3)(DMSO)2]·DMSO·1/2H2O (4), and [(AgC≡CC6H4Cl-3)4(AgCF3COO)2(L3)(DMSO)]·H2O (5), have been synthesized and characterized by X-ray crystallography. Isomorphous complexes 1 and 2 feature an infinite coordination chain composed of (C2)2Ag15 clusters alternatively linked by L1 or L2 ligands; weak intermolecular C–H···F hydrogen bonding between adjacent infinite chains results in a three-dimensional supramolecular network. Complex 3 exhibits a coordination layer structure composed of (tBuC2)2Ag7 aggregates. Compounds 4 and 5 are nearly isostructural, each possessing a ladder-like chain with a centrosymmetric (arylC2)8Ag12 cluster as its structure building unit. With the assistance of weak intermolecular hydrogen bonds, three-dimensional and two-dimensional supramolecular architectures were generated in 4 and 5, respectively. The diverse coordination modes of oligo-α-sulfanylpyrazinyl ligands Ln (n = 1, 2, 3) account for the variable framework dimensionalities observed for 1–5. Notably, complexes 3–5 provide the first examples of extended, conformationally flexible N-donor ancillary ligands incorporated into silver alkyl and aryl ethynide systems. In addition, complexes 1–5 display ligand-based photoluminescence.
Co-reporter:Dr. Sam C. K. Hau ;Dr. Thomas C. W. Mak
Chemistry - A European Journal 2013 Volume 19( Issue 17) pp:5387-5400
Publication Date(Web):
DOI:10.1002/chem.201204225
Abstract
Single-crystal X-ray diffraction of a series of ten crystalline silver(I)–trifluoroacetate complexes that contained designed ligands, each of which was composed of an aromatic system that was functionalized with terminal and internal ethynyl groups and a vinyl substituent, provided detailed information on the influence of ligand disposition and orientation, coordination preferences, and the co-existence of different types of silver(I)–carbon bonding interactions (silver–ethynide, silver–ethynyl, silver–ethenyl, and silver–aromatic) on the construction of coordination networks that were consolidated by argentophilic and weak inter/intramolecular interactions. The complex AgL10⋅6 AgCF3CO2⋅H2O⋅ MeOH (HL10=1-{[4-(prop-2-ynyloxy)-3-vinylphenyl]ethynyl}naphthalene) is the first reported example that exhibits all four kinds of silver(I)–carbon bonding interactions in the solid state.
Co-reporter:Sam C. K. Hau ; Ping-Shing Cheng
Journal of the American Chemical Society 2012 Volume 134(Issue 6) pp:2922-2925
Publication Date(Web):January 27, 2012
DOI:10.1021/ja211438q
The multinuclear metal–ligand supramolecular synthon R–C≡C⊃Agn (R = alkyl, cycloalkyl; n = 3, 4, 5) has been employed to construct two high-nuclearity silver ethynide cluster compounds, [Cl6Ag8@Ag30(tBuC≡C)20(ClO4)12]·Et2O (1) and [Cl6Ag8@Ag30(chxC≡C)20(ClO4)10](ClO4)2·1.5Et2O (chx = cyclohexyl) (2), that bear the same novel Cl6Ag8 central core. The synthesis of 1 made use of [Cl@Ag14(tBuC≡C)12]OH as a precursor, and its reaction with AgClO4 in CH2Cl2 resulted in an increase in nuclearity from 14 to 38. The results presented here strongly suggest that the formation of multinuclear silver ethynide cage complexes 1 and 2 proceeds by a reassembly process in solution that involves transformation of the encapsulated chloride template within a Ag14 cage into a cationic pseudo-Oh Cl6Ag8 inner core, leading to the generation of a much enlarged Cl6Ag8@Ag30 cluster within a cluster. To our knowledge, this provides the first example of the conversion of a silver cluster into one of higher nuclearity via inner-core transformation.
Co-reporter:Yun-Peng Xie and Thomas C. W. Mak
Chemical Communications 2012 vol. 48(Issue 8) pp:1123-1125
Publication Date(Web):02 Dec 2011
DOI:10.1039/C2CC16756E
In the giant mixed-metal silver(I)–ethynide cluster compound [Bz(Et)3N+]8[(Et)4N+]2[(V2O7)2@Ag44(CCtBu)14@(V32O96)], the cyclic polyoxovanadate {V32O96} located at a site takes a contorted configuration to wrap around an inner Ag44 cluster that in turn encapsulates a pair of pyrovanadate templates.
Co-reporter:Ting Hu, Chun-Li Hu, Fang Kong, Jiang-Gao Mao, and Thomas C. W. Mak
Inorganic Chemistry 2012 Volume 51(Issue 16) pp:8810-8817
Publication Date(Web):July 31, 2012
DOI:10.1021/ic3006376
Three new galloborates, namely, GaB5O8(OH)2(en)2·H2O (1), LiGa(OH)(BO3)(H2O) (2), and Rb2Ga(B5O10)(H2O)4 (3), have been synthesized by hydrothermal reactions. Compound 1 is the first example of a galloborate that contains an organic component. It crystallizes in space group P21/c, and its crystal structure exhibits an infinite zigzag chain consisting of [B5O8(OH)2]3– anions and GaO2N4 octahedra interconnected via corner sharing. Compound 2 crystallizes in space group P31c with a layered structure composed of GaO4, LiO4, and BO3 building units. Compound 3 belongs to chiral space group C2221; the basic building blocks of the structure are the [B5O10]5– cluster anion and GaO4 tetrahedron, which are interconnected to form a three-dimensional network with tunnels of Ga2B6 eight-membered rings (8-MRs) which are filled by Rb+ cations and lattice water molecules. Interestingly, Rb2Ga(B5O10)(H2O)4 displays a moderate second-harmonic generation (SHG) response comparable to that of KH2PO4 (KDP), and it is phase matchable. Band structure and optical property calculations for Rb2Ga(B5O10)(H2O)4 based on DFT methods were also performed.
Co-reporter:Yun-Peng Xie and Thomas C. W. Mak
Inorganic Chemistry 2012 Volume 51(Issue 16) pp:8640-8642
Publication Date(Web):July 31, 2012
DOI:10.1021/ic300913u
Variation of the reaction conditions with AgC≡CR (R = Ph, C6H4OCH3-4, tBu), tBuPO3H2, and AgX (X = NO3, BF4) as starting materials afforded four new silver(I) ethynide complexes incorporating the tert-butylphosphonate ligand, namely, 3AgC≡CPh·Ag2tBuPO3·AgtBuPO3H·2AgNO3 (1), 2AgC≡CC6H4OCH3-4·Ag2tBuPO3·2AgNO3 (2), [{Ag5(NO3@Ag18)Ag5}(tBuC≡C)16(tBuPO3)4(H2O)3][{Ag5(NO3@Ag18)Ag5} (tBuC≡C)16(tBuPO3)4(H2O)4]·3SiF6·4.5H2O·3.5MeOH (3), and [{Ag8(Cl@Ag14)}(tBuC≡C)14(tBuPO3)2F2(H2O)2]BF4·3.5H2O (4). Single-crystal X-ray analysis revealed that complexes 1 and 2 display different layer-type coordination networks, while 3 and 4 contain high-nuclearity silver(I) composite clusters enclosing nitrate and chloride template ions, respectively, that are supported by tBuPO32– ligands.
Co-reporter:Ping-Shing Cheng, Samipillai Marivel, Shuang-Quan Zang, Guang-Gang Gao, and Thomas C. W. Mak
Crystal Growth & Design 2012 Volume 12(Issue 9) pp:4519
Publication Date(Web):July 19, 2012
DOI:10.1021/cg300691n
Nine silver(I) complexes bearing the phenylethynide ligand and different ancillary anions, namely, double salts AgC≡CPh·AgNO3 (1), 2AgC≡CPh·AgNO3 (2), [Ag5(C≡CPh)4(DMSO)2]X [X = BF4 (3A), ClO4 (3B), PF6 (3C), AsF6 (3D), SbF6 (3E)], 2AgC≡CPh·5AgO2CCF3·4DMSO (4), and a triple salt 10AgC≡CPh·2AgOTf·AgNO3·3DMSO (5), have been synthesized and shown to possess coordination frameworks that are assembled with the supramolecular synthon Ph–C≡C⊃Agn (n = 3, 4, 5). Different argentophilic layers are found in nitrate complexes 1 and 2, which are crystallized from water and mixed water/DMSO, respectively. Difficulty was encountered in growing quality crystals of complexes 3A–3E, 4, and 5 bearing weakly coordinating anions, but DMSO proved to be a good solvent for crystallization by functioning as a coligand. The isostructural compounds 3A–3E exhibit the same type of pseudohexagonal packing of infinite silver columns, with the ancillary anionic component filling the intervening space and linking adjacent columns via weak hydrogen bonds. Three-dimensional supramolecular frameworks based on similar packing of silver chains and columns, respectively, are found in double salt 4 and triple salt 5.
Co-reporter:Jie Han, Chung-Wah Yau, Chin Wing Chan, and Thomas C. W. Mak
Crystal Growth & Design 2012 Volume 12(Issue 9) pp:4457
Publication Date(Web):July 23, 2012
DOI:10.1021/cg3006184
Four new inclusion compounds featuring an anionic layer-type host lattice constructed with guanidinium–bis(hydrogen carbonate) 2:1 rosette-ribbons that accommodate the same tetra-n-butylammonium guest species have been obtained and characterized by single-crystal X-ray analysis. In these crystal structures, an array of rosette-ribbons in parallel or nearly parallel alignment are cross-linked by selected carboxylate molecular connectors with effective bridging distances in the range 10.1–19.8 Å: 4,4′-biphenyldicarboxylate, with the longest separation between its colinear hydrogen-bonding acceptor sites in [(n-Bu)4N+]6[C(NH2)3+]6(HCO3–)6[4,4′-C12H8(COO–)2]3·6H2O (1); cyclohexane-1,4-dicarboxylate, with a nonplanar molecular skeleton in [(n-Bu)4N+]4[C(NH2)3+]8(HCO3–)6[1,4′-C6H10(COO–)2]3·8H2O (2); 4-cyanobenzoate, with a strong “Y type” hydrogen-bonding acceptor site at one end and a weak one at the other in [(n-Bu)4N+]2[C(NH2)3+]2(HCO3–)2[NCC6H4(COO–)]2·2H2O (3); and 1H-imidazole-4,5-dicarboxylate, functioning as a multiple hydrogen-bond acceptor in [(n-Bu)4N+]3[C(NH2)3+]4(HCO3–)4[H+{C3N2H–(COO–)(COOH)}2] (4). The resulting planar anionic layer in 1 becomes an undulatory one in 3 and 4. In 2, adjacent wavy layers are supported by centrosymmetric cyclic (GM+)2(H2O)4 “double molecular pillars” to yield a three-dimensional anionic host network.
Co-reporter:Yun-Peng Xie;Han Wang
Journal of Cluster Science 2012 Volume 23( Issue 3) pp:727-736
Publication Date(Web):2012 September
DOI:10.1007/s10876-012-0505-8
Variation of the reaction conditions with AgC≡CR (R = Ph, tBu), tBuPO3H2, (Et4N)VO3 and AgNO3 as starting materials afforded three isostructural globular neutral silver(I)-ethynide clusters incorporating the [(tBuPO3)4V4O8]4− unit as an integral shell component, namely {(NO3)2@Ag16(C≡CPh)4[(tBuPO3)4V4O8]2(DEF)6(NO3)2}, {(NO3)2@Ag16(C≡CtBu)4[(tBuPO3)4V4O8]2(DMF)6(NO3)2}·DMF·2H2O and {(NO3)2@Ag16(C≡CtBu)4[(tBuPO3)4V4O8]2(DMF)6(NO3)2}·{(NO3)2@Ag16(C≡CtBu)4[(tBuPO3)4V4O8]2(DMF)4(py)2(NO3)2}·DMF·5H2O, in which the central cavity of each Ag16 cluster is occupied by two nitrate ions that function as a template. Furthermore, from the reaction of AgC≡CtBu with (NH4)4[V2O4(d,l-citrate)2]·4H2O, we isolated a new high-nuclearity silver(I)-ethynide cluster [(VO4)2@Ag34(C≡CtBu)22(NO3)6]·8H2O that encapsulates a pair of templating orthovanadate ions.
Co-reporter:Ting Hu, Liang Zhao, and Thomas C. W. Mak
Organometallics 2012 Volume 31(Issue 21) pp:7539-7547
Publication Date(Web):October 31, 2012
DOI:10.1021/om300838r
Six new silver(I) double salts containing embedded 1,3-butadiyne-1,4-diide (C42–) and various types of ancillary heteroaromatic N-donor ligands, namely [{(Ag2C4)0.5(AgNO3)3(L1)}·H2O]n (1; L1 = 3-chloropyridine), [(Ag2C4)2(AgCF3CO2)9(L1)7(H2O)]n (2; L1 = 3-chloropyridine), [(Ag2C4)2(AgCF3CO2)9(L2)7(H2O)]n (3; L2 = 3-bromopyridine), [{(Ag2C4)(AgCF3CO2)5(L3)1.5(H2O)2}·H2O]n (4; L3 = 2-methylpyrazine), [(Ag2C4)(AgCF3CO2)6(L4)6] (5; L4 = 2-cyanopyridine), and [(Ag2C4)(AgCF3CO2)10(L5)8] (6; L5 = imidazole) have been synthesized and characterized by X-ray crystallography. Complex 1 exhibits a two-dimensional coordination network in which the basic building unit is a [Ag4C4Ag4] aggregate. Isomorphous complexes 2 and 3 feature a composite-chain structure with trifluoroacetate and halogen-substituted pyridine ligands surrounding a columnar silver backbone. Complex 4 is a three-dimensional coordination framework composed of silver columns cross-linked by external silver atoms and 2-methylpyrazine bridges. Complex 5 contains two nearly identical discrete supramolecular clusters, each with its [Ag4C4Ag4] core stabilized by four bridging 2-cyanopyridine ligands and three peripheral trifluoroacetates at each terminal. Complex 6 is composed of somewhat similar but larger discrete supramolecules, with its [Ag4C4Ag4] core stabilized by trifluoroacetate as well as both inner and peripheral bis(imidazole)silver units.
Co-reporter:Bo Li, Shuang-Quan Zang, Hai-Yang Li, Yang-Jie Wu, Thomas C.W. Mak
Journal of Organometallic Chemistry 2012 s 708–709() pp: 112-117
Publication Date(Web):
DOI:10.1016/j.jorganchem.2012.02.029
Co-reporter:Dr. Yun-Peng Xie ; Thomas C. W. Mak
Angewandte Chemie International Edition 2012 Volume 51( Issue 35) pp:8783-8786
Publication Date(Web):
DOI:10.1002/anie.201202195
Co-reporter:Dr. Yun-Peng Xie ; Thomas C. W. Mak
Angewandte Chemie 2012 Volume 124( Issue 35) pp:8913-8916
Publication Date(Web):
DOI:10.1002/ange.201202195
Co-reporter:Yun-Peng Xie
Journal of the American Chemical Society 2011 Volume 133(Issue 11) pp:3760-3763
Publication Date(Web):February 24, 2011
DOI:10.1021/ja1112035
Two neutral silver(I)−phenylethynide clusters incorporating the [(tBuPO3)4V4O8]4− unit as an integral shell component, namely {(NO3)2@Ag16(C≡CPh)4[(tBuPO3)4V4O8]2(DMF)6(NO3)2}·DMF·H2O and {[(O2)V2O6]3@Ag43(C≡CPh)19[(tBuPO3)4V4O8]3(DMF)6}·5DMF·2H2O, have been isolated and characterized by X-ray crystallography. The central cavities of the Ag16 and Ag43 clusters are occupied by two NO3− and three [(O2)V2O6]4− template anions, respectively.
Co-reporter:Chong-Qing Wan and Thomas C. W. Mak
Crystal Growth & Design 2011 Volume 11(Issue 3) pp:832-842
Publication Date(Web):January 25, 2011
DOI:10.1021/cg101490a
A series of silver(I) complexes of a higher homologue of di-2-pyridyl ketone, 2,6-pyridinediylbis(4-pyridinyl)methanone (abbreviated as L), consisting of {[Ag(L)(BF4)]·H2O}∞ (1), {[Ag(L)(NO3)]·H2O}∞ (2), [Ag3(L)2(NO2)3(H2O)]∞ (3), [Ag(L)]2(PF6)2 (4), {[Ag(L)(CO2CF3)]2}∞ (5), [Ag(L)]2(SO3CF3)2 (6), and [Ag(L)]2(CO2CF2CF3)2 (7), have been synthesized and characterized. Complexes 1 and 2 are isomorphous helical polymers, 3 is a metallacycle featuring a trisilver(I) core, and 4−7 are isostructural complexes containing a common dinuclear [Ag2(L)2]2+ metallacyclic skeleton. All complexes except 4 feature a common dominant intermolecular multipolar carbonyl···carbonyl interaction, which along with argentophilic Ag(I)···Ag(I), π···π, hydrogen-bonding, Ag···O═C, O(trifluoroacetate)···C═O as well as unconventional C═O···π and anion-π(pyridyl) interactions assemble the different coordination motifs (1−3, 5−7) into higher-dimensional frameworks. Three principal types of carbonyl···carbonyl interaction exhibiting antiparallel, sheared parallel, and perpendicular motifs are observed, and unusual supramolecular associations such as “···[C═O···C═O]n···” (in 1−2 and 6) and “···[C═O···C═O···π]n···” (in 3) and “C═O···C═O···C═O” (in 7) are the novel structural features established in these complexes. The geometrical parameters and role of such noncovalent interactions in the construction of the present series of supramolecular metal−organic frameworks are discussed.
Co-reporter:Chong-Qing Wan and Thomas C. W. Mak
New Journal of Chemistry 2011 vol. 35(Issue 2) pp:319-327
Publication Date(Web):11 Nov 2010
DOI:10.1039/C0NJ00631A
The new angular-shaped multidentate ligand sulfonyldipyrazine (abbreviated as L) is capable of forming diverse coordination polymeric motifs with various silver(I) salts, such as the infinite chain structure of [Ag3(L)(NO2)3]∞, (4,4) net of isomorphous {[Ag(L)](ClO4)}∞ and [Ag(L)(NO3)]∞, and three-dimensional frameworks of [Ag(L)(CF3SO3)]∞ and [Ag(L)(CF3CO2)]∞. In these complexes, sulfonyldipyrazine exhibits flexible ligation modes with its pyrazinyl N atoms bound to adjacent metal centers. The electron-deficient pyrazinyl rings and the sulfonyl group at the bend provide additional bonding sites for unconventional interactions, such as anion–π(pyrazinyl) and SO⋯π(pyrazinyl) interactions, in the supramolecular assembly of these complexes.
Co-reporter:Bo Li, Shuang-Quan Zang, Ran Liang, Yang-Jie Wu, and Thomas C. W. Mak
Organometallics 2011 Volume 30(Issue 6) pp:1710-1718
Publication Date(Web):March 3, 2011
DOI:10.1021/om2000162
A series of four new ligands bearing terminal ethynide moieties attached via pendant arms to a benzene skeleton have been used in the syntheses of four silver(I) complexes: [(Ag2L1)2·(AgCF3CO2)10·(CH3CN)2·(H2O)4·(μ2-H2O)2]·(AgBF4) (1), [(Ag2L2)·(AgCF3CO2)7·(CH3CN)·(H2O)] (2), {[(Ag2L3)·(AgCF3CO2)10·(CH3CN)6·(H2O)2·(OH)2]·(H2O)} (3), and [(Ag3L4)2·(AgCF3CO2)13·(CH3CN)5·(H2O)] (4) (H2L1 = 1,2-bis(prop-2-ynyloxy)benzene, H2L2 = 1,3-bis(prop-2-ynyloxy)benzene, H2L3 = 1,4-bis(prop-2-ynyloxy)benzene, H3L4 = 1,2,3-tris(prop-2-ynyloxy)benzene). In these compounds, the invariable appearance of the μ4- and μ5-ligation modes of the ethynide moiety affirms the general utility of the silver−ethynide supramolecular synthon Agn⊂C≡CCH2OC6H4OCH2C≡C⊃Agn (n = 4, 5) in coordination network assembly. Additionally, several conventional and unconventional silver−ethynyl, argentophilic, hydrogen-bonding, silver−aromatic, and π−π interactions play an important role in stabilizing their framework structures. In 1, Ag15 aggregates are fused together by argentophilic interaction to yield thick silver rods, which are further linked through interchain hydrogen bonds into a 2D network. In 2, butterfly-shaped Ag4 baskets are fused into silver(I) columns, which are further associated by external Ag(CF3COO)2 units and argentophilic interactions to give a metal−organic sheet; adjacent layers are then linked into a 3D metal−organic framework through face-to-face aromatic π−π interactions. In 3, Ag6−phenyl ring−Ag6 structural units are interconnected by a pair of μ4-η2,η2 trifluoroacetate groups to yield silver columns, which are further united by hydrogen bonds to give a 3D metal−organic network. Two kinds of silver rods in parallel orientation are bridged by three μ3-η1,η2 and one μ4-η2,η2 trifluoroacetate groups to generate a two-dimensional metal−organic network of 4, in which the trianion exhibits the unprecedented μ20-coordination mode.
Co-reporter:Bo Li, Shuang-Quan Zang, Can Ji, Thomas C.W. Mak
Journal of Organometallic Chemistry 2011 696(15–16) pp: 2820-2828
Publication Date(Web):
DOI:10.1016/j.jorganchem.2011.05.002
Co-reporter:Chong-Qing Wan ; Liang Zhao
Inorganic Chemistry 2010 Volume 49(Issue 1) pp:97-107
Publication Date(Web):December 8, 2009
DOI:10.1021/ic901521j
The new ligand dipyrazinyl sulfoxide (also named sulfinyldipyrazine and abbreviated as pyz2SO) and a series of its metal complexes including {[Ag(pyz2SO)](NO3)·CH3CN}∞ (1), {[Ag(pyz2SO)](PF6)}∞ (2), [Ag3(pyz2SO)2(ClO4)3]∞ (3), [Ag(pyz2SO)(CF3CO2)]∞ (4), {[Zn(pyz2SO)(H2O)4](NO3)2·H2O}∞ (5), {[Zn(pyz2SO)(H2O)2](ClO4)2}∞ (6), and {[Cd(pyz2SO)2(H2O)](ClO4)2·H2O}∞ (7) have been synthesized and characterized by single-crystal X-ray analysis. The counteranions in these complexes prefer to be embraced by a pair of π-acidic heterocyclic rings via anion−π interactions, which consequently affect the process of supramolecular assembly. Seven distinct ligation modes of pyz2SO involving various bonding combinations of the sulfoxide oxygen and/or pyrazinyl nitrogen atoms (labeled A−G) are observed. Diverse coordination motifs such as (4,4) network, ladder-type, necklace-like, linear, and zigzag-chain structures are found in 1−7. Interestingly, the sulfoxide group of the pyz2SO ligand exhibits unusual dipolar sulfinyl···sulfinyl and S═O···π(pyrazinyl) intermolecular interactions in the supramolecular assemblies of neat pyz2SO, 1, and 3−5.
Co-reporter:Xiao-Li Zhao
Inorganic Chemistry 2010 Volume 49(Issue 8) pp:3676-3678
Publication Date(Web):March 24, 2010
DOI:10.1021/ic901697f
Three polyoxometalate-based silver(I) ethynediide complexes have been obtained by hydrothermal synthesis. New types of polyoxometalate motifs are generated and stabilized in a silver-rich environment in their respective three-dimensional coordination frameworks via assembly of the polyhedral metal−ligand C2@Agn (n = 6 and 7) supramolecular synthon.
Co-reporter:Siegfried M. J. Wang, Liang Zhao and Thomas C. W. Mak
Dalton Transactions 2010 vol. 39(Issue 8) pp:2108-2121
Publication Date(Web):23 Dec 2009
DOI:10.1039/B917789B
A series of thirteen new silver(I) double and multiple salts containing 4-nitrophenylethynide (L), namely AgL·4AgCF3COO·CH3CN (1), AgL·5AgCF3COO·3CH3CN (2), 3AgL·4AgCF3COO·2CH3CN (3), 3AgL·7AgCF3COO·6CH3CN (4), AgL·3AgC2F5COO·CH3CN (5), 4AgL·4AgC3F7COO·3CH3CN (6), 2AgL·4AgCF3COO·NC(CH2)2CN (7), AgL·3AgCF3COO·CH3CN·0.5NC(CH2)4CN (8), AgL·3AgC2F5COO·CH3CN·NC(CH2)4CN (9), 4AgL·12AgCF3COO·4(m-NCC6H4CN)·H2O (10), AgL·2[CF2(CF2COOAg)2]·4.5H2O (11), AgL·CF2(CF2COOAg)2·AgCF3COO·H2O (12) and AgL·CF2(CF2COOAg)2·AgC2F5COO·H2O (13), have been synthesized and characterized by X-ray crystallography. All these compounds contain the multinuclear silver–ethynide supramolecular synthon R–CC⊃Agn (R = 4-nitrophenyl; n = 3, 4, 5). High-dimensional metal–organic frameworks are achieved in these complexes via the linkage of characteristic carboxylate-bridged infinite silver chains by nitro–silver coordination or weak interactions. In addition, the nitrophenyl group exhibits its versatile ability to form other intermolecular interactions such as nitro⋯nitro, π⋯π, and C–H⋯O hydrogen bonding to stabilize the network structure. Furthermore, several factors affecting the supramolecular architectures, including the incorporation of nitriles and/or bidentate perfluorocarboxylates as co-existing ligands are also discussed.
Co-reporter:Jie Han Dr.;Shuang-Quan Zang Dr. ;ThomasC.W. Mak Dr.
Chemistry - A European Journal 2010 Volume 16( Issue 17) pp:5078-5088
Publication Date(Web):
DOI:10.1002/chem.200903134
Abstract
A series of five complexes that incorporate the guanidinium ion and various deprotonated forms of Kemp’s triacid (H3KTA) have been synthesized and characterized by single-crystal X-ray analysis. The complex [C(NH2)3+]⋅[H2KTA−] (1) exhibits a sinusoidal layer structure with a centrosymmetric pseudo-rosette motif composed of two ion pairs. The fully deprotonated Kemp’s triacid moiety in 3 [C(NH2)3+]⋅[KTA3−] (2) forms a record number of eighteen acceptor hydrogen bonds, thus leading to a closely knit three-dimensional network. The KTA3− anion adopts an uncommon twist conformation in [(CH3)4N+]⋅ 2 [C(NH2)3+]⋅[KTA3−]⋅2 H2O (3). The crystal structure of [(nC3H7)4N+]⋅ 2 [C(NH2)3+]⋅[KTA3−] (4) features a tetrahedral aggregate of four guanidinium ions stabilized by an outer shell that comprises six equatorial carboxylate groups that belong to separate [KTA3−] anions. In 3 [(C2H5)4N+]⋅ 20 [C(NH2)3+]⋅11 [HKTA2−]⋅[H2KTA−]⋅ 17 H2O (5), an even larger centrosymmetric inner core composed of eight guanidinium ions and six bridging water molecules is enclosed by a crust composed of eighteen axial carboxyl/carboxylate groups from six HKTA2− anions.
Co-reporter:Guang-Gang Gao ; Ping-Shing Cheng
Journal of the American Chemical Society 2009 Volume 131(Issue 51) pp:18257-18259
Publication Date(Web):November 30, 2009
DOI:10.1021/ja907900b
Surface functionalization of polyoxometalate anions with silver(I) tert-butylethynide in an organic solution medium has been achieved for the first time using an acid-induced facile approach. The generated neutral hybrid monomeric complexes [Ag40(C≡CtBu)22(CF3COO)12(V10O28)]·4CH3OH (1) and [Ag40(C≡CtBu)20(CF3COO)12(Mo6O22)]·2CH3OH (2) constitute members of a new silver(I)−polyoxometalate family in which the polyoxometalate anion is embedded in a polyhedral silver(I) cluster assembled by multiple argentophilic Ag···Ag interactions.
Co-reporter:Liang Zhao and Thomas C. W. Mak
Inorganic Chemistry 2009 Volume 48(Issue 14) pp:6480-6489
Publication Date(Web):June 23, 2009
DOI:10.1021/ic900346p
Three pairs of complementary nitrogen heteroaryl ligands [2,6-(C≡C)2-py and 2-C≡C-pym; 2,5-(C≡C)2-py and 2-C≡C-pyz; 3,5-(C≡C)2-py and 5-C≡C-pym (py = pyridine, pyz = pyrazine, pym = pyrimidine)], wherein a ring nitrogen atom in one is interchanged with a carbon atom bearing an ethynyl substituent in the other, have been used to generate seven silver(I) complexes (1−7), in which silver infinite chains and two-dimensional coordination networks bridged by heteroaryl ethynide ligands were obtained as pre-programmed. The relative positions and bonding preference between the ethynide group and ring nitrogen atom act as controlling factors to produce various structural building units for the formation of multidimensional coordination networks. The fusion of C≡C⊃Agn (n = 3, 4) building units yields multinuclear silver aggregates in 1−6 whose nuclearities range from seven to twelve. The crystal structure of 7 displays a honeycomb layer composed of Ag4 baskets alternately linked by pyrimidinyl-5-ethynide ligands. In addition, complex 1 features an infinite chain composed of an alternate arrangement of twist-boat water hexamers and bridging silver atoms.
Co-reporter:Jie Han, Liang Zhao, Chung-Wah Yau and Thomas C. W. Mak
Crystal Growth & Design 2009 Volume 9(Issue 1) pp:308
Publication Date(Web):December 2, 2008
DOI:10.1021/cg800487b
A series of nine compounds including tetra-alkylammonium 5-nitrobarbiturates and their urea and thiourea adducts have been obtained and characterized by single crystal X-ray analysis. The hydrogen-bonded networks in these compounds feature three different kinds of dimeric 5-nitrobarbiturate linkages (para-to-para, ortho-to-ortho and para-to-ortho), which are stabilized by formation of the cyclic urea dimer supramolecular synthon. In four thiourea complexes, the 5-nitrobarbiturate dimer is the dominant building unit, while in the urea complexes no such dimer is present due to the comparable hydrogen bonding capability of urea and 5-nitrobarbiturate. The main connection modes in the urea complexes are the traditional head-to-tail and shoulder-to-shoulder types, as well as a specific nitro-urea hydrogen motif. In [2(CH3)4N+]·[2(C4H2N3O5)−]·(NH2)2CS (3), the thiourea molecule uses its syn and anti hydrogen atoms as a clamp and strut, respectively, to connect two nearly parallel hydrogen-bonded 5-nitrobarbiturate zigzag ribbons. Comparison of the nine crystal structures substantiates the versatility of 5-nitrobarbiturate as a building block in the construction of hydrogen-bonded crystalline networks. The present study also shows that the size of the tetra-alkylammonium cation plays an important role in the generation and stabilization of inclusion complexes.
Co-reporter:Shuang-Quan Zang, Ping-Shing Cheng and Thomas C. W. Mak
CrystEngComm 2009 vol. 11(Issue 6) pp:1061-1067
Publication Date(Web):10 Feb 2009
DOI:10.1039/B900308H
In a series of five new silver(I) ethynide complexes, the invariable appearance of the μ4 and μ5 ligation modes of the ethynide moiety affirms the general utility of the supramolecular synthon p-X–C6H5OCH2C≡C⊃Agn (X = I, Br; n = 4, 5) in the assembly of coordination networks, in which the silver⋯halogen–aryl interaction plays an important role.
Co-reporter:Chong-Qing Wan, Jie Han and Thomas C. W. Mak
New Journal of Chemistry 2009 vol. 33(Issue 4) pp:707-712
Publication Date(Web):05 Dec 2008
DOI:10.1039/B818344A
Three types of intermolecular S⋯π interaction geometry are identified in the crystal structures of four sulfanyl-triazine derivatives bearing pendant heterocyclic rings, in which the triazinyl, pyrazinyl, pyrimidinyl and pyridyl rings are found to exhibit different affinities for the divalent S atom.
Co-reporter:Siegfried M.J. Wang, Thomas C.W. Mak
Polyhedron 2009 28(13) pp: 2684-2692
Publication Date(Web):
DOI:10.1016/j.poly.2009.05.004
Co-reporter:Xu-Dong Chen Dr.;Chong-Qing Wan;Herman H.-Y. Sung Dr.;IanD. Williams ;ThomasC.W. Mak
Chemistry - A European Journal 2009 Volume 15( Issue 26) pp:6518-6528
Publication Date(Web):
DOI:10.1002/chem.200900010
Co-reporter:Shuang-Quan Zang, Jie Han and Thomas C. W. Mak
Organometallics 2009 Volume 28(Issue 9) pp:2677-2683
Publication Date(Web):April 10, 2009
DOI:10.1021/om801143q
A new ligand bearing a pendant terminal ethynide moiety attached to a phenyl ring skeleton has been used in the synthesis of four silver(I) complexes: [(AgL)2·(AgCF3CO2)4·(H2O)·(CH3CN)] (1), [(AgL)2·(AgCF3CO2)4·(H2O)] (2), [(AgL)·(AgC2F5CO2)8·(H2O)2·(CH3CN)2] (3), and [(AgL)·(AgC2F5CO2)6·(H2O)3]·H2O (4) (HL = prop-2-ynyloxybenzene). In this series of compounds, the invariable appearance of the μ4 and μ5 ligation modes of the ethynide moiety affirms the general utility of the silver−ethynide supramolecular synthon C6H5OCH2C≡C⊃Agn (n = 4, 5) in coordination network assembly. For 1, square-pyramidal Ag5 baskets are fused into silver(I) columns, which are further associated through hydrogen bonding and aryl π···π and oxo lone pair···π interactions to give a 3D supramolecular structure. Interestingly, in situ recrystallization of 1 in its mother liquor leads to loss of the coordinated acetonitrile molecule to yield the 2D metal−organic network of 2, in which the phenyl ring coordinates to a bent trinuclear silver(I) unit. In 3 and 4, an unusual silver−aromatic interaction involving a η3-phenyl ring links 2D networks to generate a 3D metal−organic framework.
Co-reporter:Shuang-Quan Zang and Thomas C. W. Mak
Inorganic Chemistry 2008 Volume 47(Issue 16) pp:7094-7105
Publication Date(Web):July 19, 2008
DOI:10.1021/ic800576b
Five new ligands bearing terminal ethynide moieties attached via pendant arms to a naphthyl skeleton have been used in the synthesis of eight silver(I) complexes. In these compounds, the invariable appearance of the μ4 and μ5 ligation modes of the ethynide moiety reaffirms the general utility of the silver−ethynide supramolecular synthons R−C≡C⊃Agn and Agn⊂C≡C−R−C≡C⊃Agn (n = 4, 5) in coordination network assembly, even when the R group is conformationally flexible. Besides the silver−ethynyl and silver−aromatic interactions, several unconventional intermolecular interactions (argentophilicity, anion−π, C−H···π, and C≡N···π) also make their appearance.
Co-reporter:Chong-Qing Wan, Gui-Sheng Li, Xu-Dong Chen and Thomas C. W. Mak
Crystal Growth & Design 2008 Volume 8(Issue 11) pp:3897-3901
Publication Date(Web):September 26, 2008
DOI:10.1021/cg800476a
In situ carbonyl hydration of di-2-pyrazinylmethanone (2-C4H3N2)2CO upon metal coordination leads to three isostructural mononuclear copper(II) complexes Cu(L1′)2X2·nH2O (L1′ = (2-C4H3N2)2C(OH)2, n = 4.5; X = ClO4−, BF4−, PF6−) whose three-dimensional supramolecular host network, which contains honeycomb-like channels that accommodate water guests, is constructed from the consolidation of mononuclear Cu(L1′)22+ metallotectons via cooperative hydrogen-bonding and anion-π interactions. Replacing one pyrazinyl ring of L1′ by a less π-acidic pyridyl ring to yield a related ligand leads to the formation of Cu(L2′)2(ClO4)2·4H2O 4 (L2′ = (2-C4H3N2)(2-C5H4N)C(OH)2), which exhibits a different supramolecular framework of lesser stability on account of reduced anion-π bonding interaction.
Co-reporter:Chong-Qing Wan, Thomas C.W. Mak
Inorganica Chimica Acta 2008 Volume 361(Issue 5) pp:1496-1502
Publication Date(Web):1 April 2008
DOI:10.1016/j.ica.2007.08.002
The new ligand di-2-pyrazinylmethanone (di-2-pyrazinyl ketone), (2-C4H3N2)2CO, has been synthesized, and two silver(I) coordination polymers of its hydrated gem-diol (2-C4H3N2)2C(OH)2, namely {Ag[(2-C4H3N2)2C(OH)2](CF3SO3)}∞ (1) and {Ag[(2-C4H3N2)2C(OH)2](CF3CO2)}∞ (2), have been characterized by X-ray crystallography. A (4,4) net was found in compound 1. In the case of 2, the silver(I) atom functions as a rare five-connected node to conjunct the (2-C4H3N2)2C(OH)2 ligands into an extended coordination network which can be viewed as an α-Po topology of the NaCl-type.The new ligand di-2-pyrazinylmethanone (di-2-pyrazinyl ketone), (2-C4H3N2)2CO, has been synthesized, and two silver(I) coordination polymers of its hydrated gem-diol (2-C4H3N2)2C(OH)2, namely {Ag[(2-C4H3N2)2C(OH)2](CF3SO3)}∞ (1) and {Ag[(2-C4H3N2)2C(OH)2](CF3CO2)}∞ (2), have been characterized by X-ray crystallography.
Co-reporter:Liang Zhao, Xu-Dong Chen and Thomas C. W. Mak
Organometallics 2008 Volume 27(Issue 11) pp:2483-2489
Publication Date(Web):April 29, 2008
DOI:10.1021/om701201m
In a series of four silver(I) complexes containing nitrate and ethynide ligands attached to different aromatic rings, namely, [Ag2(m-C≡CC6H4C≡C)]·5AgNO3·3H2O (1), 2[(AgC≡C)2-2,3-C4H2S]·10AgNO3 (2), [(AgC≡C)-3-py]·3AgNO3 (3), and 2[(AgC≡C)-2-pyz]·6AgNO3·3H2O (4) (py = pyridine; pyz = pyrazine), intermolecular π−π interaction dominates the assembly of supramolecular synthons Ag4⊂C≡C−R−C≡C⊃Ag4 and R—C≡C⊃Ag4 to give infinite columnar structures exhibiting distinct π−π stacking modes. The decrease in aromaticity of the ring moieties in 1, 3, and 4 is accompanied by weakened π−π stacking, transforming from the parallel face-to-face mode in 1, through a displaced stacked arrangement in 3, to the edge-to-face contact in 4. Replacement of one ethynide moiety of m-phenylenediethynide ligand in 1 by nitrogen coordination sites on the aromatic ring in 3 and 4 was found to have a limited effect on interrupting the whole π−π stacking infinite column.
Co-reporter:Shuang-Quan Zang, Liang Zhao and Thomas C. W. Mak
Organometallics 2008 Volume 27(Issue 11) pp:2396-2398
Publication Date(Web):May 3, 2008
DOI:10.1021/om800165x
The three silver(I) coordination polymers [(Ag2L)(AgNO3)6(H2O)] (1), [(Ag2L)0.5(AgCF3CO2)4(H2O)2] (2), and [(Ag2L)(AgCF3CO2)7(CH3CN)3(μ2-H2O)] (3) have been constructed from the flexible multifunctional dianionic ligand L (H2L = 2,2′-bis(prop-2-ynyloxy)biphenyl), providing experimental evidence of coexisting uncommon intermolecular interactions (cation−π and π−π in 1; cation−π and anion−π in 2; C≡N···π and C−H···π in 3) that stabilize their framework structures.
Co-reporter:Liang Zhao;Chong-Qing Wan;Jie Han;Xu-Dong Chen ;Thomas C.W. Mak Dr.
Chemistry - A European Journal 2008 Volume 14( Issue 33) pp:10437-10444
Publication Date(Web):
DOI:10.1002/chem.200800968
Abstract
Supramolecular networks constructed with the tBuCC⊃Agn (n=4 or 5) metal–ligand synthon and trifluoroacetate have been transformed through the introduction of ancillary terminal nitrile ligands, from acetonitrile through propionitrile to tert-butyronitrile, giving rise to a 2D coordination network in AgCCtBu⋅3 AgCF3CO2⋅H2O (1), a 2D hydrogen-bonded network in AgCCtBu⋅5 AgCF3CO2⋅4 CH3CN⋅H2O (2), a 2D hybrid coordination/hydrogen-bonded network in AgCCtBu⋅3 AgCF3CO2⋅CH3CH2CN⋅2 H2O (3), and another 2D coordination network in AgCCtBu⋅4 AgCF3CO2⋅ (CH3)3CCN⋅2 H2O (4). Concomitantly, the linkage modes between adjacent ethynide-bound Agn aggregates in these compounds are also changed. A layer-type hydrogen-bonded host lattice in isostructural AgCCtBu⋅4 AgCF3CO2⋅(R4N)(CF3CO2)⋅ 2 H2O (R4=BnMe3, 5; R4=Et4, 6; R4=nPr4, 7) is obtained by introducing quaternary ammonium cations as guest templates, which occupy the interstices and thereby mediate the interlayer separation. Use of the bulky nBu4N+ cation leads to disruption of the host network in AgCCtBu⋅4 AgCF3CO2⋅3[(nBu4N)(CF3CO2)]⋅H2O (8) with generation of a discrete dense nido-Ag5 cluster.
Co-reporter:Thomas C. W. Mak Dr.;Liang Zhao
Chemistry – An Asian Journal 2007 Volume 2(Issue 4) pp:456-467
Publication Date(Web):16 FEB 2007
DOI:10.1002/asia.200600386
The invariant appearance of the μ8 coordination mode for the C42− dianion in its silver(I) complexes, with four silver(I) atoms attached to each terminal ethynide moiety, implies that the Ag4⊂CCCC⊃Ag4 species may be considered as a new type of supramolecular synthon for the construction of 1D, 2D, and 3D coordination polymers. This Focus Review covers recent results on the synthesis and structural characterization of silver(I) arylethynide and alkylethynide complexes, which established the existence and utility of analogous polynuclear supramolecular synthons RCC⊃Agn (R=aryl or alkyl; n=4, 5) and Agn⊂C2RC2⊃Agn (R=p-, m-, o-C6H4; n=4, 5). The interplay of silver–ethynide bonding, which can be classified into σ, π, and mixed (σ,π) types, with argentophilicity, π–π stacking, and other weak interactions highlights the complexity and challenge in building coordination networks of silver ethynide complexes.
Co-reporter:Liang Zhao;Miao Du Dr.;Thomas C. W. Mak Dr.
Chemistry – An Asian Journal 2007 Volume 2(Issue 10) pp:1240-1257
Publication Date(Web):4 SEP 2007
DOI:10.1002/asia.200700193
A series of 13 silver(I) double and multiple salts containing 1,3-butadiynediide, C42−, were synthesized by dissolving the silver carbide Ag2C4 in a concentrated aqueous solution of one or more of the silver salts AgNO3, AgCF3CO2, AgC2F5CO2, AgF, AgBF4, and AgPF6. The 1,3-butadiynediide anion invariably adopts a μ4,μ4 coordination mode in these compounds, which indicates that the Ag4⊂CCCC⊃Ag4 moiety can be used as a new type of metalloligand supramolecular synthon for the construction of coordination networks. Fine-tuning with various ancillary anionic ligands caused the Ag4 aggregate at each ethynide terminus to adopt a butterfly-shaped, planar, or barblike configuration, within which the silver–ethynide interactions can be classified into three types: σ, π, and mixed (σ,π). The effect of coexisting nitrile ligands and quaternary ammonium salts on supramolecular assembly with the above synthon was also explored. The hydrolysis of PF6− and BF4− led to the formation of the quadruple salt Ag2C4⋅4 AgNO3⋅AgPF2O2⋅Ag3PO4 and a novel (F)2(H2O)18 hydrogen-bonded tape in the triple salt Ag2C4⋅2 AgF⋅ 10 AgC2F5CO2⋅CH3CN⋅12 H2O, respectively. The largest silver–ethynide cluster aggregate described to date, (C4)3@Ag18, occurs in 3 Ag2C4⋅ 12 AgC2F5CO2⋅5[(BnMe3N)C2F5CO2]⋅ 4 H2O (Bn=benzyl).
Co-reporter:Liang Zhao;Xiao-Li Zhao Dr.;Thomas C. W. Mak Dr.
Chemistry - A European Journal 2007 Volume 13(Issue 20) pp:
Publication Date(Web):23 APR 2007
DOI:10.1002/chem.200700006
Structural correlation in a series of eight silver(I) complexes bearing substituted phenylethynide ligands was systematically investigated through variation of the position or steric bulk of substituents on the aromatic ring. All coordination frameworks are constructed with the supramolecular synthon ArCC⊃Agn (Ar=4-MeC6H4, 3-MeC6H4, 2-MeC6H4, 4-tBuC6H4, 3,5-(CF3)2C6H3; n=4, 5), and the presence of coexisting ligands was found to influence the supramolecular assembly. The role of π–π stacking, CH⋅⋅⋅π and Ag–C(aromatic) interactions in stabilizing the coordination networks is also discussed.
Co-reporter:Xiao-Li Zhao, Lin-Ping Zhang and Thomas C. W. Mak
Dalton Transactions 2006 (Issue 25) pp:3141-3146
Publication Date(Web):28 Mar 2006
DOI:10.1039/B601767C
Reactions of the pyridine N-oxide ligands L, L2 and L3 with the silver acetylenediide-containing system under hydrothermal conditions gave rise to four silver–acetylenediide complexes bearing interesting C2@Agn motifs: (Ag2C2)2(AgCF3CO2)8(L1)3.5 (1), (Ag2C2)2(AgCF3CO2)8(L2)2 (2), (Ag2C2)(AgCF3CO2)4(L3) (3) and [(Ag7(C2)(CF3SO3)3(L3)2(H2O)2]·2CF3SO3 (4) (L = nicotinic acid N-oxide, L1 = pyridine N-oxide, L2 = 1,2-bis(4-pyridyl)ethane N,N′-dioxide, L3 = 1,3-bis(4-pyridyl)propane N,N′-dioxide), which exhibit new distorted polyhedral C2@Agn cage motifs. Complex 1 has a pair of acetylenediide dianions encapsulated in a Ag14 aggregate composed of three polyhedral parts, whereas 2 contains an irregular (C2)2@Ag13 double cage. In 3, the basic building unit is a centrosymmetric (C2)2@Ag12 double cage with each component single cage taking the shape of a highly distorted triangulated dodecahedron with one missing vertex. As to complex 4, the core is a C2@Ag7 single cage in the form of a slightly distorted monocapped trigonal prism with four cleaved edges that include all three vertical sides. Furthermore, in the silver-rich environment, the pyO-type ligands are induced to exhibit unprecedented coordination modes, such as the µ5-O,O,O,O′,O′ ligation mode of L2 in 2 and the µ4-O,O,O′,O′ mode of L3 in 3 and 4.
Co-reporter:Xu-Dong Chen, Thomas C.W. Mak
Inorganica Chimica Acta 2006 Volume 359(Issue 2) pp:685-689
Publication Date(Web):20 January 2006
DOI:10.1016/j.ica.2005.08.027
2-Pyridinyl-4-pyridinylmethanone (L) has been shown to behave as a monodentate ligand via its 4-pyridyl ring in three new metal(II) complexes, all of which exhibit supramolecular architectures assembled through weak interactions including hydrogen bonding and π–π stacking. Effects of the inorganic anions on the structure of the Cd(II) complexes of L are also discussed.2-Pyridinyl-4-pyridinylmethanone (L) has been shown to behave as a monodentate ligand via its 4-pyridyl ring in three new metal(II) complexes, all of which exhibit supramolecular architectures assembled through weak interactions including hydrogen bonding and π–π stacking. Effects of the inorganic co-ligands on the structure of the Cd(II) complexes of L are also discussed.
Co-reporter:Xiao-Li Zhao, Thomas C.W. Mak
Inorganica Chimica Acta 2006 Volume 359(Issue 11) pp:3451-3458
Publication Date(Web):1 August 2006
DOI:10.1016/j.ica.2005.07.043
Five new silver(I) triple salts: (Ag2C2)(AgNO3)4(AgL1)2(L1H)2 (1), (Ag2C2)(AgCF3CO2)2(AgL1)2(L1H)1/2 (2), [(Ag2C2)(AgCF3CO2)4(L2)(H2O)] · (L2H2) (3), (Ag2C2)(AgNO3)3(AgL3)2 (4), and [(Ag2C2)(AgCF3CO2)4(AgL3)2(H2O)2] · H2O (5) (L1H = nicotinic acid, L2H = isonicotinic acid, L3H = 2-pyrazinecarboxylic acid) have been synthesized by the hydrothermal method. All five compounds contain polyhedral silver(I) cages each encapsulating an acetylenediide dianion, C22-. In 1, C2@Ag8 cages in the shape of bicapped trigonal prisms are interlinked by nitrate, L1, and L1H ligands into a three-dimensional architecture. In 2, silver(I) columns generated from fusion of triangulated dodecahedra are linked by L1 into a layer structure. Compound 3 provides a rare example of a (L2H2)+-pillared three-dimensional structure via hydrogen bonding. In 4, nitrate ligands together with L3 link the C2@Ag7 cages into a three-dimensional architecture. Compound 5 also exhibits a three-dimensional architecture generated from trifluoroacetate and L3-linked C2@Ag8 cages.New silver(I) triple salts (Ag2C2)(AgNO3)4(AgL1)2(L1H)2 (1), (Ag2C2)(AgCF3CO2)2(AgL1)2(L1H)1/2 (2), [(Ag2C2)(AgCF3CO2)4(L2)(H2O)] · (L2H2) (3), (Ag2C2)(AgNO3)3(AgL3)2 (4), and [(Ag2C2)(AgCF3CO2)4(AgL3)2(H2O)2] · H2O (5) (L1H = nicotinic acid, L2H = isonicotinic acid, L3H = 2-pyrazinecarboxylic acid) synthesized by the hydrothermal method have been shown to exhibit a variety of supramolecular structures. Compound 3 provides an interesting example of (L2H2)+-pillared three-dimensional architecture via hydrogen bonding.
Co-reporter:Liang Zhao;Wai-Yeung Wong Dr.
Chemistry - A European Journal 2006 Volume 12(Issue 18) pp:
Publication Date(Web):18 APR 2006
DOI:10.1002/chem.200501449
Novel μ5-η1,η1,η1,η1,η2 and μ5-η1,η1,η1,η2,η2 coordination modes of alkyl and aryl ethynide moieties are found in silver(I) complexes 1–5, and the metal–ligand distances can be classified into σ, π and mixed (σ,π) types. With the consistent square-pyramidal capping Ag5 baskets of the ethynide moiety as supramolecular synthons, a series of two- and three-dimensional coordination networks are obtained.
Co-reporter:Xu-Dong Chen, Miao Du and Thomas C. W. Mak
Chemical Communications 2005 (Issue 35) pp:4417-4419
Publication Date(Web):09 Aug 2005
DOI:10.1039/B507363D
In the pair of helical conformational polymorphs of the coordination polymer {[AgL](CF3SO3)}∞
(L = 2-pyridinyl-3-pyridinylmethanone), the 21 helices of opposite chirality in one supramolecular isomer are stacked alternately to form a racemate, while the 41 helices in the other are assembled homochirally by inter-chain argentophilic interaction to generate a conglomerate.
Co-reporter:Xu-Dong Chen and Thomas C. W. Mak
Chemical Communications 2005 (Issue 28) pp:3529-3531
Publication Date(Web):24 Jun 2005
DOI:10.1039/B505919D
An ordered sequence of the coordinating ability of a series of polyatomic monoanions has been established on the basis of structural parameters derived from their interaction with a disilver(I) metallacyclophane skeleton in isostructural complexes.
Co-reporter:C. Malla Reddy, L. Sreenivas Reddy, Srinivasulu Aitipamula, Ashwini Nangia, Chi-Keung Lam and Thomas C. W. Mak
CrystEngComm 2005 vol. 7(Issue 5) pp:44-52
Publication Date(Web):05 Jan 2005
DOI:10.1039/B416985A
The title amide host 1 crystallizes in the wheel-and-axle framework via amide N–H⋯O dimer and includes several aromatic and aliphatic guest molecules in cavities of 40 Å2 size between supramolecular axles. Bulky triphenylmethyl groups make it impossible for the second NH donor to engage in strong hydrogen bonding and this promotes a weak intermolecular N–H⋯π interaction in inclusion adducts of aromatic and hydrophobic guests (structure type 1, guest = xylenes, chloro/bromo-toluene). On the other hand, the N–H⋯π interaction is absent for guests with CO groups because of stronger N–H⋯Oguest hydrogen bonding (type 2, guest = EtOAc, MeNO2). Crystal structures of both types are virtually identical except for the rotation of CONH2 group that transforms the N–H⋯π interaction to the N–H⋯O hydrogen bond. In addition to controlling the occurrence of the weak N–H⋯π hydrogen bond through host⋯guest recognition, a third structure type with N–H⋯Ohost and N–H⋯π hydrogen bonds is present in the anisole adduct. Amide group conformations, strong and weak hydrogen bonds, and close packing of aromatic residues determine the three structure types of composition 1·(guest)0.5 in space group P. The CH2Cl2 solvate, 1·(CH2Cl2)1.5, has a different crystal packing in space group C2/c with guest molecules included in channels between amide dimers and also between Ph3C groups. The design and control of the weak N–H⋯π hydrogen bond are shown for the first time in a family of isomorphous crystal structures. Infrared spectroscopy and variable temperature X-ray diffraction are consistent with the hydrogen bond nature of the N–H⋯π interaction. Differential scanning calorimetry and thermal gravimetric analysis confirm the functional behavior of inclusion host 1 and show differences in the release of CH2Cl2 molecules from the two types of channels. Crystal latttice energies follow the order structure type 3 < type 2 < type 1 in the range of −90 to −76 kcal mol−1 per host molecule.
Co-reporter:Xu-Dong Chen, Thomas C.W. Mak
Inorganica Chimica Acta 2005 Volume 358(Issue 4) pp:1107-1112
Publication Date(Web):1 March 2005
DOI:10.1016/j.ica.2004.11.024
Two pairs of stable mononuclear single-strand helical complexes were obtained through controlled self-assembly using 2,6-pyridinediylbis(2-pyridinyl)methanone (L) and copper(II) salts. CuL(NO3)2 (1) and [CuL′(H2O)](NO3)2 (2) represent a pair in which L takes the diketo form in 1 but hydrolyzed in 2, while CuLCl2 (3) and [CuL″Cl]Cl (4) constitute another pair in which L remains intact in 3 but solvolyzed in 4. A mechanism of the metal-promoted hydrolysis and solvolysis of ligand L with asymmetric induction is proposed through studies on the crystal structures of these complexes.Two pairs of stable mononuclear single-strand helical complexes were obtained through controlled self-assembly using 2,6-pyridinediylbis(2-pyridinyl)methanone (L) and copper(II) salts. A mechanism of the metal-promoted hydrolysis and asymmetric solvolysis of L is proposed on the basis of the crystal structures of the complexes.
Co-reporter:Xiao-Li Zhao;Quan-Ming Wang Dr.
Chemistry - A European Journal 2005 Volume 11(Issue 7) pp:
Publication Date(Web):15 FEB 2005
DOI:10.1002/chem.200401182
Ten polymeric silver(I) double salts containing embedded acetylenediide: [(Ag2C2)2(AgCF3CO2)9(L1)3] (1), [(Ag2C2)2(AgCF3CO2)10(L2)3]⋅H2O (2), [(Ag2C2)(AgCF3CO2)4(L3)(H2O)]⋅0.75 H2O (3), [(Ag2C2)1.5(AgCF3CO2)7(L4)2] (4), [(Ag2C2)(AgCF3CO2)7(L5)2(H2O)] (5), [(Ag2C2) (AgC2F5CO2)7(L1)3(H2O)] (6), [(Ag2C2)(AgCF3CO2)7(L1)3(H2O)]⋅2 H2O (7), [(Ag2C2)(AgC2F5CO2)6(L3)2] (8), [(Ag2C2)2(AgC2F5CO2)12(L4)2(H2O)4]⋅H2O (9), and [(Ag2C2)(AgCF3CO2)6(L3)2(H2O)]⋅H2O (10) have been isolated by varying the types of betaines, the perfluorocarboxylate ligands employed, and the reaction conditions. Single-crystal X-ray analysis has shown that 1–4 all have a columnar structure composed of fused silver(I) double cages, with C22− species embedded in its stem and an exterior coat comprising anionic and zwitterionic carboxylates. For 5 and 6, single silver(I) cages are linked into a beaded chain through both types of carboxylate ligands. In 7, two different coordination modes of L1 connect the silver(I) polyhedra into a chain. For 8, the μ2-O,O′ coordination mode of L3 connects the silver(I) double cages into a chain. Compound 9 exhibits a two-dimensional architecture generated from the cross-linkage of double cages by C2F5CO2−, L4, and [Ag2(C2F5CO2)2] units. Similar to 9, 10 is also a two-dimensional structure, which is formed by connecting the chains of linked double cages through [Ag2(CF3CO2)2] bridging.
Co-reporter:Sumod George, Ashwini Nangia, Chi-Keung Lam, Thomas C. W. Mak and Jean-François Nicoud
Chemical Communications 2004 (Issue 10) pp:1202-1203
Publication Date(Web):20 Apr 2004
DOI:10.1039/B402050B
Crystalline nitrodiphenyl ureas adopt the N–H⋯O tape α-network only when stabilization accrues from the I⋯O2N or CC–H⋯O2N synthon, otherwise the urea⋯nitro motif is preferred; soft, weak interactions can direct polar self-assembly in strong N–H⋯O hydrogen-bonded crystals.
Co-reporter:Chi-Keung Lam, Mei-Fun Cheng, Chi-Lun Li, Jie-Peng Zhang, Xiao-Ming Chen, Wai-Kee Li and Thomas C. W. Mak
Chemical Communications 2004 (Issue 4) pp:448-449
Publication Date(Web):18 Dec 2003
DOI:10.1039/B312545A
The non-benzenoid aromatic D5h and enediolate C2v form of C5O52− have been stabilized by hydrogen bonding with urea and 1,3-dimethylurea, respectively, in the host lattices of two novel crystalline inclusion compounds.
Co-reporter:Chi-Keung Lam, Tze-Lock Chan and Thomas C. W. Mak
CrystEngComm 2004 vol. 6(Issue 50) pp:290-292
Publication Date(Web):01 Sep 2004
DOI:10.1039/B412162G
The hitherto unknown 3-thioallophanate ion has been generated in situ and stabilized by hydrogen bonding with thiourea in the host lattice of the new inclusion compound [(n–C4H9)4N+]H2NCSNHCO2−·(NH2)2CS.
Co-reporter:Xiao-Li Zhao and Thomas C. W. Mak
Dalton Transactions 2004 (Issue 20) pp:3212-3217
Publication Date(Web):27 Aug 2004
DOI:10.1039/B406711H
New silver(I) double salts (Ag2C2)(AgCF3CO2)8(3-pyCONH2)2(H2O)4 (1), [(Ag2C2)(AgCF3CO2)4(4-pyCONH2)(H2O)]·H2O (2), (Ag2C2)(AgCF3CO2)6(3-pyCONH2)4 (3), (Ag2C2)(AgCF3CO2)6(3-pyCN)2 (4) and (Ag2C2)(AgCF3CO2)4(4-pyCN)2 (5) (n-pyCONH2 is pyridine-n-carboxamide, n-pyCN is n-cyanopyridine; n=3, 4) have been synthesized by the hydrothermal method. All five compounds contain polyhedral silver(I) cages each encapsulating a C22− dianion. Compounds 1, 3, 4 and 5 exhibit three-dimensional structures, whereas compound 2 is a two-dimensional network. The structure of 1 is constructed from the linkage of a branched-tree architecture via hydrogen bonds. Unlike 4 and 5, which involve the connection of n-cyanopyridine (n=3, 4) with silver columns, 3 results from the linkage of discrete silver cages via pyridine-3-carboxamide.
Co-reporter:Lin-Ping Zhang, Wen-Jie Lu and Thomas C. W. Mak
Chemical Communications 2003 (Issue 22) pp:2830-2831
Publication Date(Web):17 Oct 2003
DOI:10.1039/B307604K
The new flexible spacer ligand 1,3-bis(4-pyridyl)propane-N,N′-dioxide forms three classes of isomorphous compounds with metal(II) thiocyanates at controlled ligand–metal molar ratios, and its μ3-O,O,O′ mode leads to a pair of coordination networks having the same (4, 4) topological characteristics but different mono- and di-nuclear nodes.
Co-reporter:Chi-Keung Lam and Thomas C. W. Mak
Chemical Communications 2003 (Issue 21) pp:2660-2661
Publication Date(Web):08 Oct 2003
DOI:10.1039/B306649E
In the new inclusion compound [(C2H5)4N+]2·CO32−·7(NH2)2CS, the carbonate ion is surrounded by twelve convergent NH donor groups from six thiourea molecules to form a hydrogen-bonded aggregate shaped like two concave three-leaved propellers sharing a common core, whereas in [(n-C3H7)4N+]2·C2O42−·4(NH2)2CS the oxalate ion serves as a hub for binding four thiourea molecules to generate a cross-shaped structural motif.
Co-reporter:Hai-Tao Wu, Song-Lin Li and Thomas C. W. Mak
Dalton Transactions 2003 (Issue 9) pp:1666-1668
Publication Date(Web):04 Apr 2003
DOI:10.1039/B301639K
The crystal structures of pyridiniodithioacetate (pydta)
1 and its first stable metal complex, [Cd(pydta)2Cl2]
2, have been determined; intermolecular C–H⋯S hydrogen bonds play a dominant role in determining the molecular packing of both structures, and 2 is further stabilized by the presence of weak C–H⋯Cl interactions.
Co-reporter:Quan-Ming Wang and Thomas C. W. Mak
Dalton Transactions 2003 (Issue 1) pp:25-27
Publication Date(Web):26 Nov 2002
DOI:10.1039/B210057F
The new triple salt (PhCH2NMe3)4[Ag17(C2)2(CF3CO2)16(NO3)(H2O)4]
(1) features an asymmetric silver(I) double cage constructed from the edge-sharing of a triangulated dodecahedron and a monocapped square antiprism, and an anionic columnar structure is generated with an unprecedented μ5-ligation mode of the nitrate ion.
Co-reporter:Quan-Ming Wang Dr.
Chemistry - A European Journal 2003 Volume 9(Issue 1) pp:
Publication Date(Web):18 DEC 2002
DOI:10.1002/chem.200390002
Five silver(I) double salts containing embedded acetylenediide, [Ag([12]crown-4)2][Ag10(C2)(CF3CO2)9([12]crown-4)2(H2O)3]⋅H2O (2), [Ag2C2⋅5 AgCF3CO2⋅(benzo[15]crown-5)⋅2 H2O]⋅0.5 H2O (3), [Ag4([18]crown-6)4(H2O)3][Ag18(C2)3(CF3CO2)16(H2O)2.5]⋅2.5 H2O (4), [Ag2C2⋅6 AgC2F5CO2⋅2([15]crown-5)]2 (5), and [(Ag2C2)2⋅(AgC2F5CO2)9⋅([18]crown-6)2⋅(H2O)3.5]⋅H2O (6), have been isolated by varying the types of crown ethers and anions employed. Single-crystal X-ray analysis has shown that complex 2 is composed of winding anionic chains with sandwiched [Ag([12]crown-4)2]+ ions accommodated in the concave cavities between them. In 3, silver(I) double cages each sandwiched by a couple of benzo[15]crown-5 ligands are linked by {Ag2(CF3CO2)2} bridges to form a one-dimensional structure. For 4, an anionic silver column is generated through fusion of two kinds of silver polyhedra (triangulated dodecahedron and bicapped trigonal antiprism), and the charge balance is provided by aqua-ligated [Ag([18]crown-6)]+ ions. Complex 5 is a centrosymmetric hexadecanuclear supermolecule composed of two [(η5-[15]crown-5)2(C2@Ag7)(μ-C2F5CO2)5] moieties connected through a {Ag2(C2F5CO2)2} bridge. Compound 6 is a discrete supermolecule containing an asymmetric (C2)2@Ag13 cluster core capped by two [18]crown-6 ligands in μ3-η5 and μ4-η6 ligation modes.
Co-reporter:Quan-Ming Wang Dr.
Chemistry - A European Journal 2003 Volume 9(Issue 4) pp:
Publication Date(Web):11 FEB 2003
DOI:10.1002/chem.200390107
Co-reporter:Quan-Ming Wang and Thomas C. W. Mak
Chemical Communications 2002 (Issue 22) pp:2682-2683
Publication Date(Web):16 Oct 2002
DOI:10.1039/B208298E
Unprecedented η3
π-donor behavior of the benzyltrimethylammonium ion is observed in the polymeric silver(I) complex [(PhCH2NMe3)Ag7(C2)(CF3CO2)6]n that comprises a columnar backbone constructed from the fusion of Ag8 square antiprisms each enclosing an acetylide dianion.
Co-reporter:Ram K. R. Jetti, Praveen K. Thallapally, Ashwini Nangia, Chi-Keung Lam and Thomas C. W. Mak
Chemical Communications 2002 (Issue 9) pp:952-953
Publication Date(Web):02 Apr 2002
DOI:10.1039/B200152G
The title molecule forms a honeycomb network of molecular and nitro-trimer synthons with guest species included in the hexagonal voids.
Co-reporter:Hai-Bin Song, Zheng-Zhi Zhang and Thomas C. W. Mak
Dalton Transactions 2002 (Issue 7) pp:1336-1343
Publication Date(Web):07 Mar 2002
DOI:10.1039/B109191N
The reaction of N-[(diphenylphosphino)methyl]-2-pyridinamine and N-cyclohexyl-N-[(diphenylphosphino)methyl]-2-pyridinamine with palladium(II), copper(I) and silver(I) salts and iron pentacarbonyl in different stoichiometric ratios yielded a series of complexes that display various coordination modes, including a novel P,N(amine),N(pyridyl)-bridging mode in a dinuclear silver complex which is consolidated by the argentophilic interaction.
Co-reporter:C. Malla Reddy, Ashwini Nangia, Chi-Keung Lam and Thomas C. W. Mak
CrystEngComm 2002 vol. 4(Issue 58) pp:323-325
Publication Date(Web):17 Jul 2002
DOI:10.1039/B202297D
The title host–guest crystal structure is designed to contain an N–H⋯π interaction. The crystal structure is stabilised by an N–H⋯O hydrogen-bonded amide dimer and weak N–H⋯π and C–H⋯O hydrogen bonds. The phenyl rings of triphenylmethyl groups interact via the edge-to-face herringbone T-motif.
Co-reporter:Wen-Jie Lu, Lin-Ping Zhang, Hai-Bin Song, Quan-Ming Wang and Thomas C. W. Mak
New Journal of Chemistry 2002 vol. 26(Issue 6) pp:775-781
Publication Date(Web):13 May 2002
DOI:10.1039/B111660F
The new ligand 1,2-bis(4-pyridyl)ethane-N,N′-dioxide (L) was used to generate five lanthanide(III) coordination networks of three structural types: (i) the isomorphous pair {[Ln(L)3]·(ClO4)3·(H2O)}∞
(Ln=Er, 1; Yb, 2) comprises two interpenetrating α-polonium nets in which each lanthanide(III) ion is in a rare homoleptic distorted octahedral coordination environment; (ii) an unprecedented mat-like pattern of three interwoven (6,3) nets is found in isomorphous {[Ln(NO3)3(L)1.5]·H2O}∞
(Ln=Er, 3; Yb, 4); (iii)
{[La(NO3)3(L)
(CH3OH)]·
CH3OH·CH2Cl2}∞, 5, is built of an offset stacking of distorted square grids. The complex [Er(L′)0.5(H2O)3(C2O4)](ClO4)·L′·6H2O·(dioxane)0.5
(L′=trans-1,2-bis(4-pyridyl)ethene-N,N′-dioxide), 6, is composed of (6,3) nets in which the Er(III) ions are bridged by both L′ ligands and oxalate ions.
Co-reporter:Quan-Ming Wang, Hung Kay Lee and Thomas C. W. Mak
New Journal of Chemistry 2002 vol. 26(Issue 5) pp:513-515
Publication Date(Web):18 Apr 2002
DOI:10.1039/B202709G
A new mixed-valent silver complex [AgII(tmc)][AgII(tmc)(H2O)]2·[AgI11(C2)(CF3CO2)12(H2O)4]2
(tmc=1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane) was synthesized by adding tmc to a concentrated aqueous solution of silver trifluoroacetate containing dissolved silver acetylide. Single-crystal X-ray analysis revealed that the resulting [AgII(tmc)]2+ and [AgII(tmc)(H2O)]2+ complex cations induce the self-assembly of a centrosymmetric anionic cluster dimer from the Ag(I), C22− and CF3CO2− species. A new type of cluster core [C2@Ag8]Ag was observed, which takes the form of a bicapped trigonal prism with a pendant silver atom attached to one edge.
Co-reporter:Ren-Wang Jiang, Shuang-Cheng Ma, Zhen-Dan He, Xue-Song Huang, Paul Pui-Hay But, Hua Wang, Siu-Pang Chan, Vincent Eng-Choon Ooi, Hong-Xi Xu, Thomas C.W Mak
Bioorganic & Medicinal Chemistry 2002 Volume 10(Issue 7) pp:2161-2170
Publication Date(Web):July 2002
DOI:10.1016/S0968-0896(02)00072-X
Further investigation of the active components of the chloroform fraction of the seeds of Caesalpinia minax led to the isolation of a new cassane furanoditerpenoid, caesalmin H (1), together with two known furanoditerpenoid lactones, caesalmin B (2) and bonducellpin D (3). Reduction of the naturally abundant caesalmin D (9), E (10) and F (11) resulted in three new furanoditerpenoid derivatives 4–6. Phytochemical study of the stem of the same plant and subsequent reduction afforded two friedelane triterpenoids (7–8), which were identified by spectroscopic methods. Compounds 1–2 and 4–8 were corroborated by single crystal X-ray analysis. The factors governing the reduction of cassane furanoditerpenoids and friedelane triterpenoids were investigated by correlating the crystallographic results with density functional theory. The inhibitory activities of 2–8 on the Para3 virus were evaluated by cytopathogenic effects (CPE) reduction assay.Three cassane fuanoditerpenoids 1–3 and a friedelane triterpenoid (7) were isolated from seed and stem of Caesalpinia minax, respectively. The antiviral activities of these natural compounds and their reductive products 4–6 and 8 were assessed by CPE reduction assay.
Co-reporter:Ren-Wang Jiang, Wen-Cai Ye, Ka-Yan Woo, Jiang Du, Chun-Tao Che, Paul Pui-Hay But, Thomas C.W Mak
Journal of Molecular Structure 2002 Volume 642(1–3) pp:77-84
Publication Date(Web):4 December 2002
DOI:10.1016/S0022-2860(02)00390-3
The molecular structures of two flavones, wogonin (1) and mikanin (2), and two biflavonoids, cupressuflavone (3) and neochamaejasmin A (4), were determined by single-crystal X-ray analysis. The intermolecular π–π interactions in 1–4 and the flavanones alpinetin (5) and naringenin (6) were investigated. Compounds 1–4 feature offset face-to-face intermolecular π–π interactions with centroid–centroid distances ranging from 3.70 to 3.81 Å and displacement angles ranging from 2.7 to 9.9°.
Co-reporter:Quan-Ming Wang Dr.
Angewandte Chemie International Edition 2002 Volume 41(Issue 21) pp:
Publication Date(Web):31 OCT 2002
DOI:10.1002/1521-3773(20021104)41:21<4135::AID-ANIE4135>3.0.CO;2-C
The largest known silver(I) cluster with encapsulated acetylide ions, (Et4N)6[{(Ag2C2)2(AgCF3CO2)8(CF3CO2)3(H2O)2}2], and an infinite anionic silver(I) column with co-intercalation of cyanide and acetylide ions, (Et4N)3[(Ag2C2)2(AgCN)(AgCF3CO2)11(CF3CO2)3(H2O)6] (see picture; black dumbbells C22−, cross-hatched dumbbells CN−), have been synthesized and subsequently characterized by X-ray single-crystal structure analysis.
Co-reporter:Quan-Ming Wang Dr.
Angewandte Chemie 2002 Volume 114(Issue 21) pp:
Publication Date(Web):4 NOV 2002
DOI:10.1002/1521-3757(20021104)114:21<4309::AID-ANGE4309>3.0.CO;2-Z
Der größte bekannte Silber(I)-Cluster mit eingeschlossenen Acetylid-Ionen, (Et4N)6[{(Ag2C2)2(AgCF3CO2)8(CF3CO2)3(H2O)2}2], und eine endlose anionische Silber(I)-Säule mit eingeschlossenen Cyanid- und Acetylid-Ionen, (Et4N)3[(Ag2C2)2(AgCN)(AgCF3CO2)11(CF3CO2)3(H2O)6] (siehe Bild; schwarze Hanteln: C22−, schraffierte Hanteln: CN−), wurden synthetisiert und durch Einkristall-Röntgenbeugung charakterisiert.
Co-reporter:Qi Li, Hai-Yan Hu, Chi-Keung Lam, Thomas C.W. Mak
Journal of Supramolecular Chemistry 2002 Volume 2(4–5) pp:473-478
Publication Date(Web):August–October 2002
DOI:10.1016/S1472-7862(03)00069-8
New inclusion complexes 3[(C2H5)4N+C4H3N2OS−]·(NH2)2CS·H2O (1) and (n-C3H7)4N+C4H3N2OS−·(NH2)2CS·2H2O (2) have been prepared and characterized by X-ray crystallography. In the crystal structure of 1, thiourea molecules, 2-thiouracil anions and water molecules generate a layer structure extending parallel to the (101) family of planes that involve typical O–H···O, N–H···O, O–H···S and N–H···S, N–H···N−hydrogen bonds, as well as weak C–H···O and C–H···S hydrogen bonds. The tetraethylammonium cations are arranged orderly between the stacked layers in a sandwich-like packing mode. Complex 2 features a three-dimensional host lattice containing intersecting open channels extending along the [001], [110] and [10] directions that are constructed through conventional hydrogen bonds. The tetra-n-propylammonium cations are accommodated in a zigzag fashion within each channel.New inclusion compounds are reported; thiourea molecules, 2-thiouracil anions and water molecular construct 2D or 3D H-bonded host frameworks which accommodate guest tetraalkylammonium cations.
Co-reporter:Hai-Bin Song, Quan-Ming Wang, Zheng-Zhi Zhang and Thomas C. W. Mak
Chemical Communications 2001 (Issue 17) pp:1658-1659
Publication Date(Web):16 Aug 2001
DOI:10.1039/B102717B
A novel luminescent acetylenediide-bridged tetranuclear
copper(I) complex
[Cu4(μ-Ph2Ppypz)4(μ4-
η1,η2-CC)](ClO4)2
[Ph2Ppypz = 2-(diphenylphosphino-6-pyrazol-1-yl)pyridine]
has been synthesized and structurally characterized by X-ray
crystallography.
Co-reporter:Chi-Keung Lam and Thomas C. W. Mak
Chemical Communications 2001 (Issue 17) pp:1568-1569
Publication Date(Web):09 Aug 2001
DOI:10.1039/B104386M
The C5O52− and
relatively unstable C6O62− dianions,
each serving as a hub for binding with a set of convergent NH donor groups
of four phenylurea molecules, have been generated in situ and
stabilized in nearly isostructural hydrogen-bonded host lattices.
Co-reporter:Quan-Ming Wang and Thomas C. W. Mak
Chemical Communications 2001 (Issue 9) pp:807-808
Publication Date(Web):09 Apr 2001
DOI:10.1039/B009765I
In the mixed-valent complex
[AgII(tmc)(BF4)][AgI6(C2
)(CF3CO2)5(H2O)]·
H2O, a [AgII(tmc)(BF4)]+1∞
cationic column induces the assembly of a novel, anionic zigzag chain
constructed from edge-sharing of silver(I) triangulated
dodecahedra each enclosing a C22− species.
Co-reporter:Ren-Wang Jiang, Shuang-Cheng Ma, Paul P. H. But and Thomas C. W. Mak
Organic & Biomolecular Chemistry 2001 (Issue 22) pp:2920-2923
Publication Date(Web):29 Oct 2001
DOI:10.1039/B107473N
Spirocaesalmin, a novel rearranged vouacapane diterpenoid that exhibits significant activity against respiratory syncytial virus, possesses a new carbon skeleton with a spiro-CD ring system.
Co-reporter:Ren-Wang Jiang, Paul P.H But, Shuang-Cheng Ma, Thomas C.W Mak
Phytochemistry 2001 Volume 57(Issue 4) pp:517-521
Publication Date(Web):June 2001
DOI:10.1016/S0031-9422(01)00134-0
Two furanoditerpenoid lactones, were isolated from the seeds of Caesalpinia minax Hance. Their structures and stereochemistry have been established by spectral data and single crystal X-ray analysis.Furanoditerpenoid lactones, caesalmin A and B, were isolated from the seeds of Caesalpinia minax Hance. Their structures and stereochemistry were established by spectroscopic methods and single crystal X-ray analyses.
Co-reporter:Chi-Keung Lam
Angewandte Chemie International Edition 2001 Volume 40(Issue 18) pp:
Publication Date(Web):14 SEP 2001
DOI:10.1002/1521-3773(20010917)40:18<3453::AID-ANIE3453>3.0.CO;2-U
The nonbenzenoid aromatic D6h and enediolate C2v valence tautomers of the relatively unstable rhodizonate dianion (see picture) have been generated in situ and stabilized by hydrogen bonding with (3-hydroxyphenyl)urea and 1,1′-ethylenediurea, respectively, in two novel crystalline inclusion compounds.
Co-reporter:Chi-Keung Lam
Angewandte Chemie 2001 Volume 113(Issue 18) pp:
Publication Date(Web):14 SEP 2001
DOI:10.1002/1521-3757(20010917)113:18<3561::AID-ANGE3561>3.0.CO;2-U
Das nichtbenzolische, aromatische D6h- und das Endiolat-C2v-Valenztautomer des relativ instabilen Rhodizonat-Anions (siehe Bild) wurden in situ erzeugt und durch Wasserstoffbrückenbindung mit (3-Hydroxyphenyl)harnstoff bzw. 1,1′-Ethylendiharnstoff in Form zweier neuartiger kristalliner Einschlussverbindungen stabilisiert.
Co-reporter:Cheng-Yong Su Dr.;Xiao-Ping Yang;Bei-Sheng Kang
Angewandte Chemie 2001 Volume 113(Issue 9) pp:
Publication Date(Web):3 MAY 2001
DOI:10.1002/1521-3757(20010504)113:9<1775::AID-ANGE17750>3.0.CO;2-Q
Co-reporter:Quan-Ming Wang
Angewandte Chemie 2001 Volume 113(Issue 6) pp:
Publication Date(Web):14 MAR 2001
DOI:10.1002/1521-3757(20010316)113:6<1164::AID-ANGE11640>3.0.CO;2-H
Co-reporter:Quan-Ming Wang and Thomas C. W. Mak
Chemical Communications 2000 (Issue 15) pp:1435-1436
Publication Date(Web):12 Jul 2000
DOI:10.1039/B003821K
The novel silver(I) triple salts
AgCN·AgF·4AgCF3CO2·2L (L = MeCN
or 2H2O) exhibit the same type of layer structure, in which
[F@Ag6] units each representing a fluoride-centred octahedral
silver cage are interconnected by
μ4-κC,κC∶κN
,κN-cyanide and
μ4-O,O∶O′,O
′-trifluoroacetato bridges.
Co-reporter:Ram K. R. Jetti, Feng Xue, Thomas C. W. Mak and Ashwini Nangia
Organic & Biomolecular Chemistry 2000 (Issue 6) pp:1223-1232
Publication Date(Web):08 May 2000
DOI:10.1039/A909827E
4-Tritylbenzoic acid crystallises via the carboxy dimer supramolecular synthon to produce a wheel-and-axle host lattice that includes different aromatic solvents in its microporous framework. The clathrate structures were characterised by single crystal X-ray diffraction. Solvents like xylenes, chlorobenzene and anisole are included in a channel of cross-sectional area 42 Å2 with 2∶1 host–guest stoichiometry while mesitylene occupies a channel of 71 Å2 as a 1∶1 clathrate. The host architecture is robust and yet adaptive. The carboxy dimer synthon together with the phenyl–phenyl interactions (edge-to-face, ef and offset face-to-face, off) produce recurring, zigzag tapes of wheel-and-axle supermolecules. A plethora of aromatic ef and off motifs in the intra- and inter-tape regions modulate the cavity area to accommodate solvents of different size/shape. The ability to tune the pore volume and still retain the target wheel-and-axle topology is a notable feature in this family of isomorphous structures. The unsolvated acid adopts a different crystal packing with the triphenylmethyl groups filling the voids in the structure.
Co-reporter:Cheng-Yong Su, Bei-Sheng Kang, Qing-Chuan Yang and Thomas C. W. Mak
Dalton Transactions 2000 (Issue 12) pp:1857-1862
Publication Date(Web):22 May 2000
DOI:10.1039/B001236J
Two three-dimensional frameworks composed of doubly interpenetrating networks of the same topology but different stereoisomeric structures have been constructed from self-assembly of the chiral building block, Δ- or Λ-[Nd(ntb)2]3+, with different spacers bipy and bpen (ntb = tris(2-benzimidazolylmethyl)amine, bipy = 4,4′-bipyridyl, bpen = trans-1,2-bis(4-pyridyl)ethylene). In the crystal structure of [Nd(ntb)2][ClO4]3·3bipy·2H2O the spacer bipy connects [Nd(ntb)2]3+ cations of the same handedness to generate a chiral network Δ3-Δ . . . (or Λ3-Λ . . .){[Nd(ntb)2]3+· 3bipy}∞, which is interpenetrated further by another identical network. The crystal structure of [Nd(ntb)2][ClO4]3· 3bpen·H2O shows a topologically similar but achiral framework in which each spacer bpen connects either cations of the same chirality or a pair of enantiomers, thus generating a three-dimensional racemate Δ2Λ-Λ . . . (or Λ2Δ-Δ . . .){[Nd(ntb)2]3+·3bpen}∞. Aggregation of the molecular species is effected by N–H⋯N hydrogen bonds, and the observed enantioselective self-assembly can be rationalized by π⋯π interactions between aromatic rings.
Co-reporter:Hai-Bin Song, Quan-Ming Wang, Zheng-Zhi Zhang, Thomas C.W Mak
Journal of Organometallic Chemistry 2000 Volume 605(Issue 1) pp:15-21
Publication Date(Web):30 June 2000
DOI:10.1016/S0022-328X(00)00248-5
A new non-rigid phosphine ligand, N-(diphenylphosphinomethyl)morpholine (L), has been synthesized. Its reaction with K[HFe(CO)4] results in the formation of the organometallic tridentate ligand trans-[Fe(CO)3(μ-L)2] which exhibits different coordinate modes in generating hetero-binuclear Fe0→Mn+ complexes (M=Hg(II), Cd(II), Cu(I), Ag(I)). In the copper(I) complex, both tertiary amino groups coordinate to the Cu atom at CuN1=2.059(4) and CuN2=2.055(4) Å. In the cadmium(II) complex, one tertiary N atom coordinates to the Cd atom at CdN1=2.481(3) Å, but only a weak interaction of 2.730 Å exists between the Hg and a N atom in the isomorphous mercury(II) complex.
Co-reporter:Feng Xue
Journal of Physical Organic Chemistry 2000 Volume 13(Issue 7) pp:405-414
Publication Date(Web):27 JUN 2000
DOI:10.1002/1099-1395(200007)13:7<405::AID-POC282>3.0.CO;2-B
The crystal engineering of four new layer-type molecular solids is described. The anionic host layer in 2(Et4N+)·[4,4′-(C6H4)2(COO−)2]·4H2O (1) is constructed from 4,4′-biphenyldicarboxylate (BPDC) and a square (H2O)4 cluster through O—H···O and C—H···O hydrogen bonds. A hydrogen-bonded [(H2O)8O4] cluster connects BPDC ions through O—H···O linkages to form an anionic layer in 2[(n-Pr)4N+]·[4,4′-(C6H4)2(COO−)2]·8H2O (2). In 2[(n-Pr)4N+]·[4,4′-(C6H4)2(COO−)2]·2[(NH2)2CO]·4H2O (3) and 2[(n-Bu)4N+]·[4,4′-(C6H4)2(COO−)2]·2[(NH2)2CO]·4H2O (4), BPDC forms analogous hydrogen-bonding patterns with urea and water molecules through N—H···O and O—H···O interactions, but the resulting anionic layers are pleated and nearly planar, respectively. Tetraalkylammonium cations are sandwiched between layers as guest species in all four structures. Copyright © 2000 John Wiley & Sons, Ltd.
Co-reporter:Shan-Ming Kuang, Zheng-Zhi Zhang, Kandasamy Chinnakali, Hoong-Kun Fun, Thomas C.W. Mak
Inorganica Chimica Acta 1999 Volume 293(Issue 1) pp:106-109
Publication Date(Web):2 October 1999
DOI:10.1016/S0020-1693(99)00216-9
The chiral phosphine ligand 2-(ethylphenylphosphino)pyridine (EtPhPpy, R/S mixture) reacts with Fe(CO)5 to give racemic (±)-Fe(CO)4(EtPhPpy-P), which undergoes an addition reaction with HgCl2 to afford the optically active binuclear Fe(0)–Hg(II) complexes (+)-(R)-(CO)4Fe(μ-EtPhPpy)HgCl2 and (−)-(S)-(CO)4Fe(μ-EtPhPpy)HgCl2, which can be separated manually in crystalline form. The absolute configuration of (+)-(R)-(CO)4Fe(μ-EtPhPpy)HgCl2 has been determined by single crystal X-ray analysis.
Co-reporter:Song-Lin Li, Zheng-Zhi Zhang, Thomas C.W. Mak
Inorganica Chimica Acta 1998 Volume 268(Issue 2) pp:177-187
Publication Date(Web):10 February 1998
DOI:10.1016/S0020-1693(97)05733-2
Five complexes of cadmium(II) containing an Fe → Cd donor-acceptor bond have been synthesized from the reaction of a neutral organometallic tridentate ligand trans-(CO)3Fe(Ph2Ppym)2 (Ph2Ppym = 2-(diphenylphosphino)pyrimidine) with various cadmium(II) salts and fully characterized by single-crystal X-ray analysis: [(CO)3Fe(μ-Ph2Ppym)2CdCl2]2·0.5CHCl3· 2.5thf (1) belongs to space group P1¯ with a = 12.311(4), b = 17.083(2), c = 21.994(12) Å, α = 103.34(2), β = 92.42(5), γ = 101.07(1)° and Z = 2; [(CO)3Fe(μPh2Ppym)2CdBr2]·2CH2Cl2 (2) to space group C2/c with a = 25.691(1), b = 19.953(1), c = 8.584(1) Å, β = 102.14(1)° and Z = 4; [(CO)3Fe(μ-Ph2Ppym)2Cdl2], 3, space group P2l/n with a = 13.811(1), b = 14.019(1), c = 19.738(1) Å, β = 102.26(1)° and Z = 4; [(CO)3Fe(μ-Ph2Ppym)2Cd(NCS)2]·2CH2Cl2 (4) to space group P1¯ with a = 9.986(1), b = 12.014(1), c = 20.501(1) Å, α = 98.10(1), β = 91.78(1), γ = 112.07(1)° and Z = 2; [(CO)3Fe(μ-Ph2Ppym)2Cd(CH3CN)(H2O)]·2ClO4·1.5CHCl3 (5) to space group P1¯ with a = 12.063(2), b = 12.922(2), c = 17.502(3) Å, a = 75.61(1), β = 71.14(1), γ = 79.12(1)° and Z = 2. In this series of complexes, the Fe-Cd distance lies between 2.651(2) and 2.818(1) Å which is indicative of the existence of donor-acceptor metal-metal bonding. Although the different halides have no significant influence on the Fe-Cd bond distance, the SCN− group does shorten the Fe-Cd distance owing to its delocalized electronic structure in 4. Furthermore, in the [(CO)3Fe(μ-Ph2Ppym)2Cd(MeCN)(H2O)]2+ cation of complex 5, the dative Fe → Cd bond distance, being comparable with the covalent Fe-Cd bond distance in related heterobimetallic compounds, is mainly determined by the electronic characteristics of this bond rather than the restriction imposed by the rigid bridging ligand.
Co-reporter:Guo-Cong Guo;Thomas C. W. Mak
Angewandte Chemie 1998 Volume 110(Issue 22) pp:
Publication Date(Web):12 MAR 1999
DOI:10.1002/(SICI)1521-3757(19981116)110:22<3296::AID-ANGE3296>3.0.CO;2-V
Der kantenverbrückte dreieckige Cluster [Ag3(μ-CN)3(H2O)3] (im Bild links) und die Pseudocubaneinheit [Ag3F(H2O)3] mit einer unbesetzten Ag-Position (im Bild rechts) – beide bislang unbekannt – treten in zwei neuen Doppelsalzen von AgCN und AgF mit Schichtstruktur auf. Das Cyanidion weist in diesen Verbindungen neuartige Koordinationstypen auf.
Co-reporter:Guo-Cong Guo;Gong-Du Zhou;Qi-Guang Wang;Thomas C. W. Mak
Angewandte Chemie 1998 Volume 110(Issue 5) pp:
Publication Date(Web):12 MAR 1999
DOI:10.1002/(SICI)1521-3757(19980302)110:5<652::AID-ANGE652>3.0.CO;2-K
Aus Ag2C2und einer konzentrierten wäßrigen AgF-Lösung entsteht die Titelverbindung, in der das Dianion C22− vollständig im Ag9-Käfig einer kronleuchterartigen Anordnung von zehn Silberatomen eingeschlossen ist (Strukturbild rechts).
Co-reporter:Guo-Cong Guo
Angewandte Chemie International Edition 1998 Volume 37(Issue 22) pp:
Publication Date(Web):17 DEC 1998
DOI:10.1002/(SICI)1521-3773(19981204)37:22<3183::AID-ANIE3183>3.0.CO;2-W
The edge-bridged triangular cluster [Ag3(μ-CN)3(H2O)3] (left in picture) and the pseudo-cubane moiety [Ag3F(H2O)3] with an unoccupied Ag position (right in picture)—both hitherto unknown—are found in two new layer-type double salts of AgCN and AgF that display novel types of cyanide coordination modes.
Co-reporter:Guo-Cong Guo;Gong-Du Zhou;Qi-Guang Wang
Angewandte Chemie International Edition 1998 Volume 37(Issue 5) pp:
Publication Date(Web):17 DEC 1998
DOI:10.1002/(SICI)1521-3773(19980316)37:5<630::AID-ANIE630>3.0.CO;2-K
The reaction of Ag2C2with a concentrated aqueous solution of AgF leads to the title compound, in which the dianion C22− is completely enclosed in the Ag9 cage of a chandelierlike arrangement of ten silver atoms.
Co-reporter:Guo-Cong Guo
Angewandte Chemie 1998 Volume 110(Issue 23) pp:
Publication Date(Web):12 MAR 1999
DOI:10.1002/(SICI)1521-3757(19981204)110:23<3460::AID-ANGE3460>3.0.CO;2-R
Schichten aus flächen- und kantenverknüpften trigonalen Ag6-Prismen, von denen die Hälfte mit Azidionen gefüllt sind, weist die neuartige Verbindung AgN3⋅2 AgNO3 auf (siehe Struktur im Bild). η1-Koordinierende Nitrat-Ionen befinden sich an beiden Seiten jeder Schicht.
Co-reporter:Cheng-Yong Su, Bei-Sheng Kang, Qi-Guang Wang and Thomas C. W. Mak
Dalton Transactions 2000(Issue 12) pp:NaN1833-1833
Publication Date(Web):2000/05/22
DOI:10.1039/B002411M
Self-assembly of silver(I) trifluoromethanesulfonate with the tripodal ligand tris(2-benzimidazolylmethyl)amine (ntb) affords the trinuclear complex [Ag3(ntb)2](CF3SO3)3, which exhibits a rhombohedral network formed from N–H⋯O hydrogen bonds and weak Ag⋯O interactions linking [Ag3(ntb)2]3+ cations with a novel S6-symmetric (CF3SO3−)6 cluster consolidated by multiple F⋯F interactions.
Co-reporter:Zi-Yi Chen, Dennis Y. S. Tam and Thomas C. W. Mak
Chemical Communications 2016 - vol. 52(Issue 36) pp:NaN6122-6122
Publication Date(Web):2016/04/06
DOI:10.1039/C6CC02631A
Inexpensive 1,1′-thiocarbonyldiimidazole and di(2-pyridyl) thionocarbonate have been used as respective sulfide precursors to assemble unprecedented high-nuclearity ethynide-stabilized silver(I) sulfido molecular clusters [Ag9S6@Ag36(CCtBu)32(H2O)2] [Ag(imidazole)(CH3OH)(H2O)](BF4)2·8H2O·2CH3OH (1) and [Ag120S24(PhCC)52Cl4(2-pyridone)10(H2O)8](H3O)4(SiF6)8(BF4)4·CH3OH·22H2O (2), the latter being the largest isolated silver(I) ethynide cluster reported to date.
Co-reporter:Yun-Peng Xie and Thomas C. W. Mak
Chemical Communications 2012 - vol. 48(Issue 8) pp:NaN1125-1125
Publication Date(Web):2011/12/02
DOI:10.1039/C2CC16756E
In the giant mixed-metal silver(I)–ethynide cluster compound [Bz(Et)3N+]8[(Et)4N+]2[(V2O7)2@Ag44(CCtBu)14@(V32O96)], the cyclic polyoxovanadate {V32O96} located at a site takes a contorted configuration to wrap around an inner Ag44 cluster that in turn encapsulates a pair of pyrovanadate templates.
Co-reporter:Siegfried M. J. Wang, Liang Zhao and Thomas C. W. Mak
Dalton Transactions 2010 - vol. 39(Issue 8) pp:NaN2121-2121
Publication Date(Web):2009/12/23
DOI:10.1039/B917789B
A series of thirteen new silver(I) double and multiple salts containing 4-nitrophenylethynide (L), namely AgL·4AgCF3COO·CH3CN (1), AgL·5AgCF3COO·3CH3CN (2), 3AgL·4AgCF3COO·2CH3CN (3), 3AgL·7AgCF3COO·6CH3CN (4), AgL·3AgC2F5COO·CH3CN (5), 4AgL·4AgC3F7COO·3CH3CN (6), 2AgL·4AgCF3COO·NC(CH2)2CN (7), AgL·3AgCF3COO·CH3CN·0.5NC(CH2)4CN (8), AgL·3AgC2F5COO·CH3CN·NC(CH2)4CN (9), 4AgL·12AgCF3COO·4(m-NCC6H4CN)·H2O (10), AgL·2[CF2(CF2COOAg)2]·4.5H2O (11), AgL·CF2(CF2COOAg)2·AgCF3COO·H2O (12) and AgL·CF2(CF2COOAg)2·AgC2F5COO·H2O (13), have been synthesized and characterized by X-ray crystallography. All these compounds contain the multinuclear silver–ethynide supramolecular synthon R–CC⊃Agn (R = 4-nitrophenyl; n = 3, 4, 5). High-dimensional metal–organic frameworks are achieved in these complexes via the linkage of characteristic carboxylate-bridged infinite silver chains by nitro–silver coordination or weak interactions. In addition, the nitrophenyl group exhibits its versatile ability to form other intermolecular interactions such as nitro⋯nitro, π⋯π, and C–H⋯O hydrogen bonding to stabilize the network structure. Furthermore, several factors affecting the supramolecular architectures, including the incorporation of nitriles and/or bidentate perfluorocarboxylates as co-existing ligands are also discussed.
Co-reporter:Yun-Peng Xie and Thomas C. W. Mak
Dalton Transactions 2013 - vol. 42(Issue 36) pp:NaN12872-12872
Publication Date(Web):2013/07/23
DOI:10.1039/C3DT51461G
Three new silver(I) phosphonate complexes have been synthesized from silver phenylethynide as a structure-directing precursor. Ag2(PhPO3)(H2O) displays a layer-type coordination network, Ag(3,5-dimethylpyrazole)2(PhPO3H) contains a dimeric unit, and {Ag8(dppm)4(tBuPO3)2(ClO4)(NO3)0.67(H2O)1.33}·(ClO4)2.33·(CH3OH)6.67 features an octanuclear composite cluster. We have also isolated the pyrophenylphosphonate complex Ag2[PhPO2(O)O2PPh](CH3CN), which exhibits an infinite-chain structure.
Co-reporter:Han Wang, Chong-Qing Wan and Thomas C. W. Mak
Dalton Transactions 2014 - vol. 43(Issue 19) pp:NaN7262-7262
Publication Date(Web):2014/03/06
DOI:10.1039/C3DT53344A
Two novel coordination polymers [Ag16(SO4)8][Ag4(SO4)2]3(L1)12·nH2O (n = 72) (1) and [Ag10(SO4)5(L2)4(H2O)2]·8H2O (2) based on conformationally variable oligo-α-heteroarylsulfanyl ligands 2-(pyrazin-2-ylthio)-6-(pyridin-2-ylthio)pyrazine (L1) or 2,6-bis(pyrazin-2-ylthio)pyrazine (L2) and sulfate-templated high-nuclearity Ag(I) clusters as structure-building units (SBUs) have been synthesized under mild conditions. Single-crystal X-ray analysis showed that complex 1 exhibits a porous three-dimensional framework containing Ag16(SO4)8 and Ag4(SO4)2 SBUs that are interconnected by L1 ligands, whereas 2 has a much denser network constructed from Ag10(SO4)5 SBUs and L2 linkers. To our knowledge, the Ag16(SO4)8 cluster core found in 1 is the largest sulfate-based polynuclear SBU in coordination polymers, and the 14-connected Ag10(SO4)5 in 2 is the highest-connectivity Ag(I) cluster SBU reported to date. These two complexes were fully characterized by infrared spectroscopy, elemental analysis, powder X-ray diffraction, thermogravimetric analysis and differential scanning calorimetry.
![PHOSPHINE, [1,8-NAPHTHALENEDIYLBIS(METHYLENE)]BIS[DIPHENYL-](http://img.cochemist.com/ccimg/73900/73892-41-8.png)
![PHOSPHINE, [1,8-NAPHTHALENEDIYLBIS(METHYLENE)]BIS[DIPHENYL-](http://img.cochemist.com/ccimg/73900/73892-41-8_b.png)
