Co-reporter:Yaru Qin;Qian Gao;Yanmei Chen;Wei Liu;Feng Lin
Journal of Cluster Science 2017 Volume 28( Issue 3) pp:891-903
Publication Date(Web):2017 May
DOI:10.1007/s10876-016-1083-y
The incorporation of LnIII ions into the 12-metallacrown-4 topology affords the formation of four mixed 3d-4f pentanuclear complexes of compositions [NH(C2H5)3]{[Ln(OAc)4] [12-MCMnIII(N)shi-4]}·xH2O (Ln = Sm (1), Gd (2), Tb (3), Dy (4); x = 0.5 for 1 and 3, x = 0.25 for 2, x = 0 for 4; H3shi = salicylhydroxamic acid). Compounds 1–4 were obtained from the reactions of H3shi with Mn(CH3COO)2·4H2O and Ln(NO3)3·6H2O, in the presence of N(C2H5)3. They all contain a crown-like [Mn4Ln(μ-NO)4]11+ core with four MnIII atoms being at the rim of the crown and an LnIII ion occupying the dome of the crown. The peripheral ligation about the core is provided by four η1:η1:µ acetate groups. The identity of the LnIII ions slightly affects the 12-metallacrown-4 frameworks, as demonstrated by the gradual decrease of the distances between the LnIII ions and the centres of the Mn4 planes (1.85 Å for 1, 1.81 Å for 2, 1.80 Å for 3, and 1.77 Å for 4). Variable-temperature dc magnetic susceptibility studies were carried out on polycrystalline samples of 1–4. Antiferromagnetic interactions are determined for complexes 1–4.
Co-reporter:Haifeng Zhang;Rui Liu;Jin Zhang; Dr. Yahong Li;Dr. Wei Liu;Yaping Dong
Chemistry – An Asian Journal 2017 Volume 12(Issue 5) pp:507-514
Publication Date(Web):2017/03/02
DOI:10.1002/asia.201601412
AbstractFive hexanuclear lanthanide clusters of composition [Ln6(μ4-O)2(HCOO)2L4(HL′)2(dmf)2] [Ln=Dy (1), Er (2), Ho (3), Tb (4), Gd (5); H2L=2-{[2-(hydroxymethyl)phenylimino]methyl}-6-methoxyphenol; H3L′=3-{[2-(hydroxymethyl)phenylimino]methyl}benzene-1,2-diol; H3L′ was derived in situ from the H2L ligand] were prepared under solvothermal conditions. The [Ln6] cores of 1–5 possess an unprecedented motif, namely, two tetrahedron Ln4 units sharing an edge and two vertices. The six LnIII ions of 1–5 are connected through two μ4-O anions. Magnetic susceptibility studies reveal that complex 1 exhibits frequency dependence of the alternating current susceptibility typical of single-molecule magnets. Complex 1 possesses a relatively large energy barrier of 85 K among all of the reported Dy6 single-molecule magnets.
Co-reporter:Shixiong She, Yahong Li and Wu Li
Dalton Transactions 2016 vol. 45(Issue 26) pp:10830-10835
Publication Date(Web):06 Jun 2016
DOI:10.1039/C6DT00951D
Two new 3d–4f heterometallic 1D chains of formulae {[Dy2M2L4(NO3)(H2O)3][Dy2M2L4(NO3)(CH3COO)(H2O)2]·NO3·12H2O·2C2H5OH}n [M = Ni (1); Co (2)] have been prepared using the multidentate ligand 2-{[(2-hydroxy-3-methoxyphenyl)methylidene]amino}benzoic acid (H2L), which has NO and OO′ chelating pockets that are able to selectively encapsulate LnIII and transition metal ions, respectively. Crystal structure analyses reveal that the two complexes are isostructural and display one-dimensional ladder-like double helical chain structures, in which the two single helical chains {[Dy2M2L4(NO3)(H2O)3]+} and {Dy2M2L4(NO3)(CH3COO)(H2O)2} (M = Ni(1), Co(2)) both run along the c-axis and have opposite chirality. Complexes 1 and 2 represent the first example of 3d–4f double-chain frameworks in which the compositions of the two individual chains are different. Variable temperature dc magnetic susceptibility studies reveal different strengths of ferromagnetic interactions between the magnetic centers in 1 and 2, which is mainly attributed to the different metal centers and finally results in the distinctive magnetic dynamic behaviors.
Co-reporter:Yu Li, Yaru Qin, Yong Wang, Wei Liu, Yahong Li
Polyhedron 2016 Volume 111() pp:156-160
Publication Date(Web):17 June 2016
DOI:10.1016/j.poly.2016.03.034
A new dodecanuclear cluster [CoII9CoIII3(MeOsalox)6(OAc)15(H2O)6]·2MeCN·2H2O (1) (H2MeOsalox = 3-methyloxysalicylaldoxime) was synthesized under solvothermal conditions and characterized by IR, elemental analyses (EA), single-crystal X-ray diffraction and powder XRD. Magnetic investigations reveal that complex 1 exhibits antiferromagnetic interactions between the cobalt centers.One mixed-valence cobalt(II/III) dodecanuclear cluster bridged by doubly deprotonated o-vanillin oxime and acetate anions has been assembled. Antiferromagnetic interactions between the cobalt ions are observed.
Co-reporter:Zhou Chen, Jinna Liu, Hao Pei, Wei Liu, Yanmei Chen, Jian Wu, Wu Li, and Yahong Li
Organic Letters 2015 Volume 17(Issue 14) pp:3406-3409
Publication Date(Web):June 30, 2015
DOI:10.1021/acs.orglett.5b01229
An efficient C–O amination of aryl methyl ethers has been achieved. This transformation proceeds via imine-directed Ti(IV)-mediated cross-coupling reactions between aryl methyl ethers and Ti(NR2)4 at room temperature, straightforwardly leading to a series of arylamines. This protocol features a wide substrate scope, exclusive regioselectivity, and mild reaction conditions.
Co-reporter:Jinna Liu, Yuhua Cao, Lei Li, Hao Pei, Yanmei Chen, Jinfa Hu, Yaru Qin, Yahong Li, Wu Li and Wei Liu
RSC Advances 2015 vol. 5(Issue 14) pp:10318-10325
Publication Date(Web):22 Dec 2014
DOI:10.1039/C4RA14692A
A new imidazo[1,5-a]pyridine-containing pyrrolyl ligand HL (HL = 3-(1H-pyrrol-2-yl)imidazo[1,5-a]pyridine) was synthesized and employed in the organometallic chemistry of titanium. The syntheses, structures, catalytic properties and antitumor activity of three titanium complexes supported by HL are reported. Reactions of Ti(NMe2)4 and Ti(NEt2)4 with 2 equivalents of HL, led to the production of titanium bisamido complexes TiL2(NMe2)2 (1) and TiL2(NEt2)2 (2), respectively. Treatment of Ti(OiPr)4 with 2 equivalents of HL resulted in the formation of TiL2(OiPr)2 (3). All complexes were characterized by elemental analyses and NMR studies. The solid-state structures of 2 and 3 were further established by single X-ray crystallography. The titanium bisamido complexes 1 and 2 are shown to be good pre-catalysts for the hydroamination of alkynes. Complex 1 was found to be an active catalyst for the ring-opening polymerization of ε-caprolactone. The cytotoxicity activities of 3 towards the tumor cells HCT-116, PC3 and MCF-7 were measured. Complex 3 exhibited good antitumor properties.
Co-reporter:Qian Gao, Yaru Qin, Yanmei Chen, Wei Liu, Haiyan Li, Bing Wu, Yahong Li and Wu Li
RSC Advances 2015 vol. 5(Issue 54) pp:43195-43201
Publication Date(Web):06 May 2015
DOI:10.1039/C5RA04868K
The employment of the hydroxyl-rich ligand (E)-3-((2-hydroxy-3-methoxybenzylidene)amino)propane-1,2-diol (H3L) in the chemistry of cubane-type {M4O4} clusters is reported. Three cubane-type clusters of the formula [M4(HL)4] (M = CoII (1), ZnII (2), CuII (3)) were achieved by reactions of metal acetates with H3L under solvothermal conditions. The structures of 1, 2 and 3 have been established by single-crystal X-ray diffraction studies. The tetranuclear clusters 1–3 have cubane-type [M4(μ3-OR)4]4+ cores with divalent metal atoms and deprotonated oxygen atoms (originating from the HL2− ligands) occupying alternate vertices. The luminescence studies suggest strong emission for 2 in the solid state at room temperature. The magnetic properties of 1 and 3 have been investigated. The variable-temperature dc magnetic susceptibility studies indicate ferromagnetic MII⋯MII exchange interactions for 1 and 3. The ac magnetic susceptibility investigation reveals that complex 1 shows slow magnetic relaxation (SMM) behavior.
Co-reporter:Yaru Qin, Yanmei Chen, Jinna Liu, Jingjing Zhao, Dandan Gao, Yahong Li, Wei Liu, Wu Li
Inorganic Chemistry Communications 2015 Volume 56() pp:58-61
Publication Date(Web):June 2015
DOI:10.1016/j.inoche.2015.03.047
•A ligand and two complexes were prepared by in situ metal–ligand reaction.•The magnetic property of complex 1 was studied.•The catalytic activity of complex 2 was investigated.The syntheses, characterizations and properties of two coordination complexes, [Cr3(L)3Cl6] (1) and [Cu4(L)2Br2]n (2) (HL = 2,2′,2″-(1H-imidazole-2,4,5-triyl)tripyridine) were reported. The HL ligand was unprecedentedly afforded by metal-mediated solverthermal in situ metal–ligand reaction among picolinaldehyde, ammonium acetate and metal ions. Compound 1 can be described as a bottom-opened vase-like complex with the three CrIII ions showing a triangle conformation. For complex 2, the sandwich-like [Cu4(L)2]2 + moieties are linked by bromide ions to generate a 1D chain framework. Variable-temperature magnetic studies in the temperature range of 2.0–300 K for 1 reveal antiferromagnetic CrIII⋯CrIII interactions. The catalytic activity of 2 towards the reaction of 2-butanone and ethylene glycol was also investigated; it showed a very good catalytic property allowing for the easy and high yielding preparation of 2-ethyl-2-methyl-1,3-dioxolane under mild conditions.Solvothermal in situ metal ligand reaction of picolinaldehyde, ammonium acetate and metal ions leads to generation of two structurally interesting coordination complexes supported by 2,2′,2″-(1H-imidazole-2,4,5-triyl)-tripyridine.
Co-reporter:Dr. Yanmei Chen;Qian Gao;Wenqian Chen;Dr. Dan Gao;Dr. Yahong Li;Dr. Wei Liu;Dr. Wu Li
Chemistry – An Asian Journal 2015 Volume 10( Issue 2) pp:411-421
Publication Date(Web):
DOI:10.1002/asia.201403025
Abstract
The use of pyridine-2,4-dicarboxylic acid (H2pydc) in the construction of SrII and SrII-MII (M=Co, Ni, Zn and Cu) coordination polymers is reported. Eight complexes, that is, [Sr(pydc)H2O]n (1), [MSr(pydc)2(H2O)2]n (M=Co (2), Ni (3), Zn (4)), [ZnSr(pydc)2(H2O)7]n⋅4 nH2O (5), [SrCu(pydc)2]n (6), [SrCu(pydc)2(H2O)3]n⋅2 nH2O (7), and [Cu3Sr2(pydc)4(Hpydc)2(H2O)2]n (8), have been synthesized via dexterously choosing the appropriate strontium sources and transition metal salts, and rationally controlling the temperature of the reaction systems. Complexes 1, 2 (3, 4), 6, and 8 display four types of 3-D framework structures. Complexes 5 and 7 exhibit a 2-D network and a 1-D chain structure, respectively. The 2-D complex 7 can be reversibly transformed into 3-D compound 6 through temperature-induced solvent-mediated structural transformation. The luminescent property studies indicated that complex 1 shows a strong purple luminescent emission and 4 exhibits a strong violet luminescence emission. The magnetic properties of 2, 3, and 8 were also studied. Antiferromagnetic MII⋅⋅⋅MII interactions were determined for these complexes.
Co-reporter:Yanmei Chen, Shixiong She, Qian Gao, Dandan Gao, Derong Wang, Yahong Li, Wei Liu and Wu Li
CrystEngComm 2014 vol. 16(Issue 6) pp:1091-1102
Publication Date(Web):25 Nov 2013
DOI:10.1039/C3CE41975D
The first series of heterometallic SrII–MII (M = Cu, Co, Ni and Zn) coordination polymers based on pyridine-2,5-dicarboxylic acid (H2pydc) are reported. Eight complexes of compositions, [Sr(pydc)(H2O)]n (1), [CuSr(pydc)2(H2O)4]n (2), [CoSr(pydc)2(H2O)6]2n·H2O (3), [NiSr(pydc)2(H2O)4]n·3nH2O (4), [Sr(H2O)6]n·n[Ni(pydc)2(H2O)2]·2nH2O (5), [NiSr2(pydc)3(H2O)8]n·2nH2O (6), [ZnSr(pydc)2(H2O)5]n (7) and [ZnSr2(pydc)3(H2O)10]n·2nH2O (8), have been prepared and characterized. The structures of the complexes could be controlled via rationally choosing the appropriate metal salts, adding the starting materials in different orders, and tuning the ratio of the starting materials. Eight varieties of structures, ranging from 1-D chains to 3-D networks, were obtained. The magnetic properties of 2, 3 and 6 were investigated from 2 K to 300 K. Antiferromagnetic MII⋯MII interactions were found for 2 and 6, and ferromagnetic interactions were determined for 3. The solid state luminescent properties of 1, 7 and 8 were also studied.
Co-reporter:Yanmei Chen, Qian Gao, Yonglu Liu, Yanyuan Cao, Dandan Gao, Jinna Liu, Jingjing Zhao, Yahong Li, Wei Liu and Wu Li
RSC Advances 2014 vol. 4(Issue 1) pp:147-153
Publication Date(Web):04 Nov 2013
DOI:10.1039/C3RA44489A
Four complexes of composition [Cd(4-Apha)2]n (1), [Zn2(4-Apha)4(H2O)2]·2H2O (2), [Zn(4-Apha)(CH3COO)]n (3), and [Zn4(4-Apha)4(CH3COO)4(H2O)]n·2nCH3OH (4) (4-AphaH = 4-aminophenylhydroxamic acid) have been synthesized in different solvents and characterized by X-ray diffraction, IR spectroscopy, thermal analysis and elemental analysis. X-ray crystal analysis reveals that these complexes exhibit four varieties of structures. Complex 1 displays a 1-D chain structure, and complex 2 is binuclear. Complexes 3 and 4 possess different 3-D structures. Fluorescence emissions are observed for complexes 1, 2 and 4 in solid state.
Co-reporter:Miaoshui Lin, Yuhua Cao, Hao Pei, Yanmei Chen, Jian Wu, Yahong Li and Wei Liu
RSC Advances 2014 vol. 4(Issue 18) pp:9255-9260
Publication Date(Web):23 Jan 2014
DOI:10.1039/C3RA45823G
The syntheses, structures and antitumor activity of four titanium isopropoxide complexes supported by pyrrolyl Schiff base ligands are reported. Treatment of Ti(OiPr)4 with 2 equivalents of HL1 (HL1 = N-(1H-pyrrol-2-ylmethylene)(2-pyridinyl)methanimine), HL2 (HL2 = 2-pyrrolecarbaldmethylimine), HL3 (HL3 = N-((1H-pyrrol-2-yl)methylene)(phenyl)methanimine) and HL4 (HL4 = N-((1H-pyrrol-2-yl)methylene)-2-phenylethanimine), respectively, results in the formation of Ti(OiPr)2(L1)2 (1), Ti(OiPr)2(L2)2 (2), Ti(OiPr)2(L3)2 (3) and Ti(OiPr)2(L4)2 (4). All complexes have been characterized by elemental analyses and NMR studies. The solid-state structures of complexes 1 and 3 have been further established by single X-ray crystallography. The cytotoxicity activities of 1–4 towards the tumor cells HCT-116, PC3 and MCF-7 were measured. Complexes 1, 2 and 3 showed good antitumor properties.
Co-reporter:Yanmei Chen, Qian Gao, Haifeng Zhang, Dandan Gao, Yahong Li, Wei Liu, Wu Li
Polyhedron 2014 71() pp: 91-98
Publication Date(Web):
DOI:10.1016/j.poly.2013.12.042
Co-reporter:Yanmei Chen, Lei Li, Yanyuan Cao, Jian Wu, Qian Gao, Yahong Li, Hailiang Hu, Wei Liu, Yonglu Liu, Zhenhui Kang and Jingping Li
CrystEngComm 2013 vol. 15(Issue 14) pp:2675-2681
Publication Date(Web):25 Jan 2013
DOI:10.1039/C3CE00012E
Hydrothermal reaction of CuCl2·2H2O, 3-(pyridin-2-yl)imidazo[1,5-a]pyridine (HPIP) and formaldehyde, yielded a novel mixed-valence CuI/CuII complex [L1Cu2Cl2][Cu2Cl4]·2EtOH (1·2EtOH; L1 = tetrakis(3-(pyridin-2-yl)imidazo[1,5-a]pyridin-1-yl)methane). The in situ generated quaternary carbon-containing ligand L1 was derived from CuII-mediated quadruple coupling of HPIP and formaldehyde, where the three bonds of formaldehyde were totally cleaved. 1·2EtOH can also be prepared by replacing formaldehyde by formic acid, N,N-dimethylformamide, and glyoxal, respectively. When acetic acid, which usually serves as a radical reaction inhibitor, was introduced into the reaction systems, two CuI complexes [(L2)2Cu3](CuCl2)3·2EtOH (2·2EtOH) and L3Cu2Cl2 (3) (L2 = tris(3-(pyridin-2-yl)imidazo[1,5-a]pyridin-1-yl)methane, and L3 = 1,1,2,2-tetrakis(3-(pyridin-2-yl)imidazo[1,5-a]pyridin-1-yl)ethane) were afforded. The tertiary carbon-bearing ligands L2 and L3 were generated in situ via CuII-mediated controllable cleavage of two bonds of formaldehyde, N,N-dimethylformamide and glyoxal, respectively. The plausible mechanisms for the formation of the ligands L1–L3 were proposed.
Co-reporter:Shi-Xiong She, Michael J. Zaworotko, Wei Liu, Zhu-Xiu Zhang and Yahong Li
CrystEngComm 2013 vol. 15(Issue 25) pp:5003-5006
Publication Date(Web):19 Apr 2013
DOI:10.1039/C3CE40295A
A unique silicate-bridged octanuclear dysprosium cluster [Dy8SiO4] was produced using 2-{[(2-hydroxy-3-methoxyphenyl)methylidene]amino}benzoic acid (H2L) and silicate as ligands. This intriguing compound shows field-induced slow relaxation of magnetization.
Co-reporter:Yanmei Chen, Yanyuan Cao, Wenqian Chen, Qian Gao, Lei Li, Dandan Gao, Wei Liu, Yahong Li and Wu Li
Dalton Transactions 2013 vol. 42(Issue 27) pp:10011-10018
Publication Date(Web):09 May 2013
DOI:10.1039/C3DT50453K
The employment of pyridine-2,6-dicarboxylic acid (H2pda) and imidazole (im) in the synthesis of SrII–SmIII and SrII–DyIII coordination polymers has been reported. Seven novel heterometallic coordination polymers of compositions, [Dy3Sr3(pda)7(Hpda)(H2O)9]·6H2O (1), [LnSr(pda)3(H2O)5]·Him·H2O (Ln = Sm(2), Dy(3)), [Ln2Sr(pda)6(H2O)5]·4Him·C2H5OH·nH2O (Ln = Sm(4), n = 4; Dy(5), n = 5), [Sm2Sr2(pda)5(H2O)9]·2H2O (6) and [DySr(pda)3(H2O)4]·Him·3H2O (7), have been prepared and characterized. Complexes 1, 2–3, and 6 display three varieties of 2-D structures. 4–5 and 7 exhibit two types of 1-D chain structures. The structures of the complexes could be controlled via choosing appropriate starting materials and tuning the amount of imidazole. The photo-luminescent properties of these complexes have been investigated. The results show the exclusive luminescence emission bands being characteristic of SmIII and DyIII.
Co-reporter:Shixiong She, Yanmei Chen, Michael J. Zaworotko, Wei Liu, Yanyuan Cao, Jian Wu and Yahong Li
Dalton Transactions 2013 vol. 42(Issue 29) pp:10433-10438
Publication Date(Web):09 May 2013
DOI:10.1039/C3DT50417D
A new family of octanuclear lanthanide compounds [Na2Ln6L8(C6H4NH2COO)2(C2H5OH)2(H2O)4(NO3)]·NO3·C2H5OH·nH2O [H2L = 2-{[(2-hydroxy-3-methoxyphenyl)methylidene]amino}benzoic acid; Ln = Dy (1) (n = 15); Tb (2), Gd (3) (n = 14); Sm (4) (n = 16)] have been prepared under hydrothermal conditions. The X-ray crystal structure analysis reveals that complexes 1–4 are isomorphous. The core of the structure is a [4 + 2] combination of an Ln4 cubane and an Ln2 unit. The two units are bridged by a nitrate ion, which is located in the center of the cluster and displays an unusual μ8-η2:η2:η4 tridentate bridging mode. The magnetic studies for complex 1 show that the [Na2Dy6] unit exhibits slow magnetic relaxation behavior.
Co-reporter:Yanmei Chen, Wenqian Chen, Zhenghua Ju, Qian Gao, Tao Lei, Wei Liu, Yahong Li, Dandan Gao and Wu Li
Dalton Transactions 2013 vol. 42(Issue 29) pp:10495-10502
Publication Date(Web):22 May 2013
DOI:10.1039/C3DT51184G
Eight novel SrII–LnIII heteronuclear coordination polymers based on pyridine-2,6-dicarboxylic acid (H2pda) and imidazole (im) ligands, namely, [LnSr(pda)3(H2O)5]·Him·H2O (Ln = Eu (1), Gd (2), Tb (3)), [Ln2Sr(pda)6(H2O)5]·4Him·C2H5OH·nH2O (Ln = Eu (4), n = 5; Gd (5), n = 4), [LnSr(pda)3(H2O)4]·Him·3H2O (Ln = Gd (6), Tb (7)), and [GdSr(pda)3(H2O)5]·Him·C2H5OH·3H2O (8), have been prepared by employing different amounts of imidazole. X-ray crystal structure analysis reveals that these compounds exhibit a rich structural chemistry. Complexes 1–3 possess 2-D frameworks. Complexes 4–5, 6–7, and 8 exhibit three types of 1-D chain structure. The structures of the complexes could be rationally tuned via adding different amounts of imidazole. The luminescent properties of these complexes have been investigated. The results show that EuIII and TbIII complexes exhibit intense red and green luminescence emission which are characteristics of TbIII and EuIII, respectively. Solid-state quantum yield and the lifetime of these complexes are also reported.
Co-reporter:Yanmei Chen, Lei Li, Zhou Chen, Yonglu Liu, Hailiang Hu, Wenqian Chen, Wei Liu, Yahong Li, Tao Lei, Yanyuan Cao, Zhenghui Kang, Miaoshui Lin, and Wu Li
Inorganic Chemistry 2012 Volume 51(Issue 18) pp:9705-9713
Publication Date(Web):August 24, 2012
DOI:10.1021/ic300949y
An efficient strategy for the synthesis of a wide variety of coordination complexes has been developed. The synthetic protocol involves a solvothermal in situ metal–ligand reaction of picolinaldehyde, ammonium acetate, and transition-metal ions, leading to the generation of 12 coordination complexes supported by a novel class of substituted 1-pyridineimidazo[1,5-a]pyridine ligands (L1–L5). The ligands L1–L5 were afforded by metal-mediated controllable conversion of the aldehyde group of picolialdehyde into a ketone and secondary, tertiary, and quaternary carbon centers, respectively. Complexes of various nuclearities were obtained: from mono-, di-, and tetranuclear to 1D chain polymers. The structures of the in situ formed complexes could be controlled rationally via the choice of appropriate starting materials and tuning of the ratio of the starting materials. The plausible mechanisms for the formation of the ligands L1–L5 were proposed.
Co-reporter:Lei Li;Genping Huang;Zhou Chen;Wei Liu;Xiufang Wang;Yanmei Chen;Lijuan Yang;Wu Li;Yahong Li
European Journal of Organic Chemistry 2012 Volume 2012( Issue 28) pp:5564-5572
Publication Date(Web):
DOI:10.1002/ejoc.201200829
Abstract
The successful application of gallium trichloride as a catalyst for the intermolecular hydroamination of alkynes with aromatic amines is reported. The reaction is effective with many aniline derivatives and shows exclusive selectivity for the Markovnikov products. The mechanism of the transformation was investigated by DFT calculations and a plausible pathway is proposed.
Co-reporter:Yang Zhao, Miaoshui Lin, Zhou Chen, Hao Pei, Yahong Li, Yanmei Chen, Xiufang Wang, Lei Li, Yanyuan Cao, Yong Zhang and Wu Li
RSC Advances 2012 vol. 2(Issue 1) pp:144-150
Publication Date(Web):26 Oct 2011
DOI:10.1039/C1RA00408E
A series of new titanium and zirconium amido complexes, incorporating 4,5-diphenyl-2-(2-pyridinyl)-1H-imidazole (HL1), 4,5-bis(4-chlorophenyl)-2-(2-pyridinyl)-1H-imidazole (HL2), 4,5-bis(4-methoxyphenyl)-2-(2-pyridinyl)-1H-imidazole (HL3) and 4,5-bis(2-methoxyphenyl)-2-(2-pyridinyl)-1H-imidazole) (HL4) as the ancillary ligands, have been prepared and are shown to be pre-catalysts for the hydroamination of alkynes. Treatment of Ti(NMe2)4 with 1 equivalent of HL1, HL2, HL3 and HL4, respectively, results in transamination with one dimethylamide group providing Ti(L1)(NMe2)3 (1), Ti(L2)(NMe2)3 (2), Ti(L3)(NMe2)3 (3), and Ti(L4)(NMe2)3·THF (4·THF). Reaction of Ti(NMe2)4 with 2 equivalents of HL1, HL2, HL3 and HL4, respectively, leads to production of titanium bisamido complexes Ti(L1)2(NMe2)2·THF (5·THF), Ti(L2)2(NMe2)2·THF (6·THF), Ti(L3)2(NMe2)2·THF (7·THF), and Ti(L4)2(NMe2)2 (8). Similarly, complexes Zr(L1)(NMe2)3 (9), Zr(L1)2(NMe2)2·1.5THF (10·1.5THF), Zr(L2)2(NMe2)2·0.5THF (11·0.5THF), and Zr(L3)2(NMe2)2·0.5THF (12·0.5THF) are generated by addition of 1 or 2 equivalents of the corresponding ligands to Zr(NMe2)4. All compounds have been characterized by elemental and spectroscopic analyses. The solid-state structures of compounds 2 and 6·THF have been further established by single X-ray diffraction analyses. The catalytic activities of 2 and 6·THF towards the hydroamination of alkynes were explored. Complexes 2 and 6·THF were found to be active pre-catalysts for the hydroamination reactions. Complex 2 showed higher catalytic activity and gave highly Markovnikov selective hydroamination of terminal alkynes.
Co-reporter:Miaoshui Lin, Wei Liu, Zhou Chen, Lijuan Yang, Hao Pei, Jian Wu, Xiaoyu Wan, Tao Lei and Yahong Li
RSC Advances 2012 vol. 2(Issue 8) pp:3451-3457
Publication Date(Web):29 Feb 2012
DOI:10.1039/C2RA01235A
The syntheses, structures and catalytic activities of five magnesium complexes supported by HL1 (HL1 = N-(1H-pyrrol-2-ylmethylene)(2-pyridinyl)methanimine), HL2 (HL2 = N-(1H-pyrrol-2-ylmethylene)-2-pyridineethanimine), HL3 (HL3 = 2-pyrrolecarbaldmethylimine), HL4 (HL4 = N-((1H-pyrrol-2-yl)methylene)(phenyl)methanimine) and HL5 (HL5 = N-((1H-pyrrol-2-yl)methylene)-2-phenylethanimine) are described. Treatment of MgnBu2 with 2 equiv. of HL1, HL2, HL3, HL4 and HL5, respectively, results in the formation of Mg(L1)2 (1), Mg(L2)2 (2), Mg(L3)2(THF)2 (3), Mg(L4)2(THF)2 (4) and Mg(L5)2(THF)2 (5). All complexes have been characterized by elemental analyses and NMR studies. The solid-state structures of complexes 2, 3, and 4 have been further established by single X-ray crystallography. All complexes were found to be active catalysts for the ring-opening polymerization of ε-caprolactone.
Co-reporter:Su-Yun Zhang, Wen-Qian Chen, Bin Hu, Yan-Mei Chen, Wu Li, Yahong Li
Inorganic Chemistry Communications 2012 Volume 16() pp:74-77
Publication Date(Web):February 2012
DOI:10.1016/j.inoche.2011.11.035
The tetranuclear cubane-like complex of the formula [Ni4(HL1)3(HL2)(H2O)(CH3OH)] [CH3COO]·2CH3OH·CH3CN (1) (H3L1 = 3-(2-hydroxybenzylideneamino)propane-1,2-diol; H2L2 = 3-aminoprppane-1,2-diol) has been prepared by a one-pot reaction of nickel(II) acetate, salicylaldehyde and 3-aminopropane-1,2-diol, where the H3L1 ligand was generated in situ via the condensation reaction between salicylaldehyde and 3-aminopropane-1,2-diol. The X-ray diffraction analysis of the complex showed a Ni4O4 cubane arrangement and the coordination environments of four Ni(II) ions are different from each other. Magnetic studies indicated ferromagnetic behavior for the complex. The magnetic data were fitted and the parameters were given as g = 2.43, J1 = 15.96, and J2 = 4.116.The tetranuclear cubane-like complex of the formula [Ni4(HL1)3(HL2)(H2O)(CH3OH)] [CH3COO]·2CH3OH·CH3CN (1) has been prepared and structurally characterized. Magnetic studies indicate ferromagnetic behavior for the complex.Highlights►A tetranuclear Ni4O4 cubane-like complex has been prepared and characterized. ►The coordination environments of four Ni(II) ions are different from each other. ►Magnetic studies indicate ferromagnetic behavior for the complex.
Co-reporter:Wen-Qian Chen, Yan-Mei Chen, Tao Lei, Wei Liu, Yahong Li
Inorganic Chemistry Communications 2012 Volume 19() pp:4-9
Publication Date(Web):May 2012
DOI:10.1016/j.inoche.2012.01.015
Under solvothermal conditions, one polynuclear FeIII complex of formula [Fe3{(py)C(ph)O}4Cl4][FeCl4] (1) was synthesized from reaction of phenyl-pyridine-2-yl-methanone oxime (py)C(ph)NOH with FeCl3, and one FeII/FeIII/FeII complex of composition [Fe3{(py)C(ph)NO}6][CH3COO] (2) was prepared from treatment of (py)C(ph)NOH with Fe(OAc)2. The most interesting synthetic feature of complex 1 is the in situ transformation of (py)C(ph)NOH into the (py)C(ph)O− ligand. Complexes 1 and 2 were characterized by X-ray single crystal diffraction, IR spectroscopy, and elemental analysis. X-ray analysis revealed that complex 1 contains a V-shaped FeIII core with two terminal FeIII atoms displaying distorted square-pyramidal geometries and one central FeIII ion exhibiting octahedron geometry. Complex 2 is a mixed-valence linear FeII/FeIII/FeII complex with all the three metal centers displaying distorted octahedron geometries. The low-temperature magnetic susceptibility measurement for the solid sample of 1 revealed the weak antiferromagnetic FeIII…FeIII interactions. Theoretical calculations based on density functional theory were performed using the crystal structure of complex 1.Two trinuclear complexes of formulas [Fe3{(py)C(ph)O}4Cl4][FeCl4] (1) and [Fe3{(py)C(ph)NO}6][CH3COO] (2) were prepared and characterized. Magnetic studies of 1 revealed the weak antiferromagnetic FeIII…FeIII interactions.Highlights► Two trinuclear Fe3 complexes have been prepared and characterized. ► The in situ ligand transformation was determined. ► Magnetic studies indicated antiferromagnetic behavior for complex 1.
Co-reporter:Zhi-Ping Han, Yahong Li
Inorganic Chemistry Communications 2012 Volume 22() pp:73-76
Publication Date(Web):August 2012
DOI:10.1016/j.inoche.2012.05.023
A complex of composition [CuI4CuII(mtpo)4(H2O)2Cl2]n (1) was synthesized from reaction of Hmtpo (Hmtpo = 5-methyl-[l,2,4]-triazolo-[l,5-a]-pyrimidin-7-o1) with one equivalent of CuCl2·2H2O in water at 100 °C under autogenous pressure. Complex 1 was fully characterized by X-ray single crystal diffraction, elemental analysis and IR spectroscopy. X-ray analysis reveals that complex 1 is a mixed-valence coordination polymer and displays 1-D chain structure. Compound 1 was able to heterogeneously catalyze the ketalization reaction of 2-butanone and ethylene glycol to afford 2-ethyl-2-methyl-[1,3]-dioxolane in excellent yield under mild conditions.A mixed-valence 1-D polymeric chain complex [CuI4CuII(mtpo)4(H2O)2Cl2]n (1) was synthesized and characterized. Compound 1 was able to catalyze the ketalization reaction of 2-butanone and ethylene glycol.Highlights► A mixed-valence 1-D polymeric chain complex was prepared. ► The structure of the complex was determined by X-ray analysis. ► The complex was able to catalyze the ketalization reaction.
Co-reporter:Li-Juan Yang, Tao Lei, Wei Liu, Wen-Qian Chen, Miao-Shui Lin, Lei Li, Wu Li, Yahong Li
Inorganic Chemistry Communications 2012 Volume 21() pp:12-15
Publication Date(Web):July 2012
DOI:10.1016/j.inoche.2012.03.035
A new 1-D helical chain complex [Cu(H2L)(SO4)]·CH3OH (1) (H2L = N,N-bis(3,5-dimethyl-2-hydroxybenzyl)-N-(2-pyridylmethyl)amine) was synthesized from the reaction of the tripodal tetradentate ligand H2L with CuSO4·5H2O under solvothermal conditions. Complex 1 was fully characterized by X-ray single crystal diffraction, elemental analysis and IR spectroscopy. X-ray analysis revealed that complex 1 displays a 1-D helical chain structure with the two adjacent metals being bridged by a sulfate ion. Each CuII ion is penta-coordinated and exhibits a pseudo square pyramidal geometry. The low-temperature magnetic susceptibility measurement for the solid sample of 1 revealed the ferromagnetic CuII⋯CuII interactions.A new 1-D helical chain complex [Cu(H2L)(SO4)]·CH3OH (1) was synthesized and characterized. Magnetic studies of 1 revealed the weak ferromagnetic CuII⋯CuII interactions.Highlights► A new 1-D helical chain complex was synthesized under solvothermal conditions. ► The structure of the complex was characterized. ► Magnetic studies indicated ferromagnetic CuII⋯CuII interactions.
Co-reporter:Zhou Chen, Jian Wu, Yanmei Chen, Lei Li, Yuanzhi Xia, Yahong Li, Wei Liu, Tao Lei, Lijuan Yang, Dandan Gao, and Wu Li
Organometallics 2012 Volume 31(Issue 17) pp:6005-6013
Publication Date(Web):August 15, 2012
DOI:10.1021/om300022u
An efficient Ti(NMe2)4-mediated C–C bond-forming methodology toward substituted piperazines, the basic skeleton of several biologically active natural products, has been developed. In reactions of tridentate monoanionic ligands bearing a [−HCNCH2−] linkage with Ti(NMe2)4, unusual [3 + 3] dimerized complexes through C–C coupling of the putative titanium aza-allyl complex intermediate could be obtained. These complexes contain substituted piperazine backbones and could give rise efficiently to substituted piperazine derivatives via hydrolysis. Treatment of Ti(NMe2)4 with a series of tridentate dianionic and bidentate monoanionic ligands bearing the [−HCNCH2−] moiety only generated chelated titanium complexes from ligand exchange reactions. Mechanistic studies using DFT/M06 calculations revealed that the methylene in the [−HCNCH2−] moiety of titanium complexes bearing tridentate monoanionic ligands could be deprotonated intramolecularly by dimethylamide anion with an activation energy of about 22 kcal/mol. The resulting titanium aza-allyl complexes from this β-H abstraction step then undergo a consecutive stepwise [3 + 2] cycloaddition/ring expansion reaction facilely to form the dimerized complex. However, β-H abstractions for Ti complexes bearing tridentate dianionic and bidentate monoanionic ligands were energetically demanding, as the negative charges could not be stabilized by the adjacent groups in the possible intermediates, explaining the experimental outcomes that no C–C coupled products were formed.
Co-reporter:Dr. Genping Huang;Bing Cheng;Liang Xu;Dr. Yahong Li;Dr. Yuanzhi Xia
Chemistry - A European Journal 2012 Volume 18( Issue 17) pp:5401-5415
Publication Date(Web):
DOI:10.1002/chem.201102692
Abstract
A comprehensive mechanistic study of the InCl3-, AuCl-, and PtCl2-catalyzed cycloisomerization of the 2-(haloethynyl)biphenyl derivatives of Fürstner et al. was carried out by DFT/M06 calculations to uncover the catalyst-dependent selectivity of the reactions. The results revealed that the 6-endo-dig cyclization is the most favorable pathway in both InCl3- and AuCl-catalyzed reactions. When AuCl is used, the 9-bromophenanthrene product could be formed by consecutive 1,2-H/1,2-Br migrations from the Wheland-type intermediate of the 6-endo-dig cyclization. However, in the InCl3-catalyzed reactions, the chloride-assisted intermolecular H-migrations between two Wheland-type intermediates are more favorable. These Cl-assisted H-migrations would eventually lead to 10-bromophenanthrene through proto-demetalation of the aryl indium intermediate with HCl. The cause of the poor selectivity of the PtCl2 catalyst in the experiments by the Fürstner group was predicted. It was found that both the PtCl2-catalyzed alkyne–vinylidene rearrangement and the 5-exo-dig cyclization pathways have very close activation energies. Further calculations found the former pathway would lead eventually to both 9- and 10-bromophenanthrene products, as a result of the Cl-assisted H-migrations after the cyclization of the Pt–vinylidene intermediate. Alternatively, the intermediate from the 5-exo-dig cyclization would be transformed into a relatively stable Pt–carbene intermediate irreversibly, which could give rise to the 9-alkylidene fluorene product through a 1,2-H shift with a 28.1 kcal mol−1 activation barrier. These findings shed new light on the complex product mixtures of the PtCl2-catalyzed reaction.
Co-reporter:Xue-Qing Zhang, Miao-Shui Lin, Bin Hu, Wen-Qian Chen, Li-Na Zheng, Jian Wu, Yan-Mei Chen, Feng-Ying Zhou, Ya-Hong Li, Wu Li
Polyhedron 2012 Volume 33(Issue 1) pp:273-279
Publication Date(Web):9 February 2012
DOI:10.1016/j.poly.2011.11.029
The synthesis of the anionic organolanthanide complexes supported by H2bppda (H2bppda = N,N′-bis(2-pyrrylmethylidene)-1,2-phenylenediamine) ligand via different synthetic strategies is reported. Treatment of 1:4 mixture of LnCl3(THF)3 and LiN(SiMe3)2 with 2 equivalents of H2bppda in THF gave complexes of the formula [Li(THF)4][Ln(bppda)2]·THF (Ln = Nd (1·THF), Sm (2·THF), Gd (3·THF), Dy (4·THF), Er (5·THF)) and [Li(THF)5][Yb(bppda)2] (6). Reaction of Nd(BH4)3(THF)3 with 2 equivalents of Na2bppda in THF generated [Na(THF)6][Nd(bppda)2] (7) in good yield. Treatment of 1·THF with 1 equivalent of CoCp2 in THF led to the isolation of [CoCp2][Nd(bppda)2] (8). All of the complexes have been characterized by single crystal X-ray diffraction and elemental analyses. Complexes 1·THF–5·THF are isomorphous and isostructural, and the geometry of the octa-coordinated Ln3+ ion in [Ln(bppda)2]− unit in these complexes is well described as either distorted dodecahedron or distorted bicapped trigonal prism. Lanthanide contraction was observed in 1·THF–5·THF and 6. The structures of complexes 1·THF, 7 and 8 are different from each other due to the variation of the cationic ions. The ring-opening polymerization reaction of ε-caprolactone initiated by 1·THF was conducted; it showed good activity.Graphical abstractThe synthesis and characterizations of the anionic organolanthanide complexes of formula [Li(THF)4][Ln(bppda)2]·THF (Ln = Nd (1·THF), Sm (2·THF), Gd (3·THF), Dy (4·THF), Er (5·THF)), [Li(THF)5][Yb(bppda)2] (6), [Na(THF)6][Nd(bppda)2] (7) and [CoCp2][Nd(bppda)2] (8) (H2bppda = N,N′-bis(2-pyrrylmethylidene)-1,2-phenylenediamine) were reported. The ring-opening polymerization reaction of ε-caprolactone initiated by 1·THF was also investigated; it showed good activity.Highlights► The synthesis of the anionic organolanthanide complexes was reported. ► Eight complexes were prepared and characterized. ► The polymerization of ε-caprolactone initiated by 1·THF was investigated.
Co-reporter:Yanmei Chen;Bin Hu;Bin Xu;Suyun Zhang
Russian Journal of Inorganic Chemistry 2012 Volume 57( Issue 3) pp:386-389
Publication Date(Web):2012 March
DOI:10.1134/S0036023612030059
Two new square planar complexes with the formula Co(L)2 · CH3OH (1) and Ni(L)2 · CH3OH (2) (HL = HN{C(Me)=NH}2 = N-acetimidoylacetamidine) have been synthesized by solvothermal reactions in methanol/acetonitrile. N-acetimidoylacetamidine ligand was derived from the self-condensation reaction of acetonitrile, and the reaction was promoted by the cooperation of M(II) (M = Co in 1 and M = Ni in 2) with diphenylcarbazide. 1 and 2 are characterized by single crystal X-ray diffraction, elemental analysis and infrared spectrum. Both complexes crystallize in the monoclinic space group P21/c with a = 9.329(6) Å, b = 11.494(7) Å, c = 13.040(8) Å, β = 92.945(11)°, V = 1396.3(16) Å3 and Z = 4 for 1, and a = 9.323(4)Å, b = 11.512(5) Å, c = 13.020(6)Å, β = 92.819(7)°, V = 1395.7(10)Å3 and Z = 4 for 2.
Co-reporter:Yanmei Chen, Lina Zheng, Shixiong She, Zhou Chen, Bin Hu and Yahong Li
Dalton Transactions 2011 vol. 40(Issue 18) pp:4970-4975
Publication Date(Web):21 Mar 2011
DOI:10.1039/C1DT10034C
The syntheses, crystal structures and magnetic properties are described for two novel 2D heterometallic CuII-SrII coordination polymers {Sr(H2O)6[(Im)4Cu4(pdc)4Sr(H2O)4]·6H2O}n (1) and [Cu2(H2O)2(pdc)2Sr(H2O)3]n (2) (H3pdc = 3,5-pyrazoledicarboxylic acid; Im = imidazole). The 1:1:1:5 reaction of SrCl2·6H2O, Cu(NO3)2·3H2O, H3pdc and imidazole in H2O–EtOH at 120 °C under autogenous pressure gave 1. Complex 2 was obtained from the 1:1:1 H3pdc/Sr(OH)2·8H2O/Cu(NO3)2·3H2O reaction mixture in H2O–EtOH under solvothermal conditions. Complex 1 can be described as a 2D grid-shaped network with the four CuII ions in a saddle-like conformation. In complex 2, SrII ions link metalloligands [Cu2(pdc)2(H2O)2]2− to generate a 2D layer framework. Variable-temperature solid-state dc magnetic susceptibility studies have been performed in the temperature range 2.0–300 K for complexes 1 and 2. Antiferromagnetic CuII⋯CuII exchange interactions were found for both 1 and 2.
Co-reporter:Dan Gao;Yaping Dong;Wu Li;Bin Xu;Yahong Li
Chinese Journal of Chemistry 2011 Volume 29( Issue 9) pp:1927-1932
Publication Date(Web):
DOI:10.1002/cjoc.201180335
Abstract
Experimental design (DOE) was employed to precisely determine the content of rubidium in chloride type brine of Qionglai (A city in Sichuan province, southwest of China) using atomic absorption spectrometry (AAS) technique. From the statistical analysis of six factors, it was found that K+ and Cl− were the significant interfering elements for the determination of rubidium. A model was established to eliminate the interference effects of K+ and Cl−. The experimental results indicate that, under the optimal conditions, the developed method for the rubidium determination possesses the advantages of low detection limit (0.019 µg·mL−1 at a significant level of 0.05) and higher recovery (97.2%–103.4%).
Co-reporter:Yanmei Chen, Shixiong She, Lina Zheng, Bin Hu, Wenqian Chen, Bin Xu, Zhou Chen, Fengying Zhou, Yahong Li
Polyhedron 2011 30(18) pp: 3010-3016
Publication Date(Web):
DOI:10.1016/j.poly.2011.02.017
Co-reporter:Fengying Zhou, Miaoshui Lin, Lei Li, Xueqing Zhang, Zhou Chen, Yahong Li, Yang Zhao, Jin Wu, Guimin Qian, Bin Hu, and Wu Li
Organometallics 2011 Volume 30(Issue 6) pp:1283-1286
Publication Date(Web):February 25, 2011
DOI:10.1021/om1010935
Reaction of the bis-ligand-chelated samarium complex [Sm(Hbptd)(H2bptd)] (1; H3bptd =1,9-bis(2-pyrrolyl)-2,5,8-triazanona-1,8-diene), in which a pyrrolyl ring is dangling and metal-free, with Ti(NMe2)4 yielded the heterometallic complex [Sm(Hbptd)(THF)(bptd)Ti(NMe2)2] (2). Treatment of the H3bptd ligand with 1 equiv of Ti(NMe2)4 gave the titanium amido complex [Ti(bptd)(NMe2)] (3). Complexes 2 and 3 were able to catalyze the hydroamination of phenylacetylene with 2,4-dichloroaniline and 4-methoxyaniline, and high regioselectivities were observed for the two amines. Both 1 and 2 were active catalysts for the ring-opening polymerization of ε-caprolactone. 2 showed higher activity for the polymerization reactions, due to a decrease in the coordination number of the samarium atom (from 9 in 1 to 8 in 2) by sharing its ligand with the titanium center.
Co-reporter:Alexander S. Dudnik ; Yuanzhi Xia ; Yahong Li ;Vladimir Gevorgyan
Journal of the American Chemical Society 2010 Volume 132(Issue 22) pp:7645-7655
Publication Date(Web):May 17, 2010
DOI:10.1021/ja910290c
A novel highly efficient regiodivergent Au-catalyzed cycloisomerization of allenyl and homopropargylic ketones into synthetically valuable 2- and 3-silylfurans has been designed with the aid of DFT calculations. This cascade transformation features 1,2-Si or 1,2-H migrations in a common Au-carbene intermediate. Both experimental and computational results clearly indicate that the 1,2-Si migration is kinetically favored over the 1,2-shifts of H, alkyl, and aryl groups in the β-Si-substituted Au-carbenes. In addition, experimental results on the Au(I)-catalyzed cycloisomerization of homopropargylic ketones demonstrated that counterion and solvent effects could reverse the above migratory preference. The DFT calculations provided a rationale for this 1,2-migration regiodivergency. Thus, in the case of Ph3PAuSbF6, DFT-simulated reaction proceeds through the initial propargyl-allenyl isomerization followed by the cyclization into the Au-carbene intermediate with the exclusive formation of 1,2-Si migration products and solvent effects cannot affect this regioselectivity. However, in the case of a TfO− counterion, reaction occurs via the initial 5-endo-dig cyclization to give a cyclic furyl-Au intermediate. In the case of nonpolar solvents, subsequent ipso-protiodeauration of the latter is kinetically more favorable than the generation of the common Au-carbene intermediate and leads to the formation of formal 1,2-H migration products. In contrast, when polar solvent is employed in this DFT-simulated reaction, β-to-Au protonation of the furyl-Au species to give a Au-carbene intermediate competes with the ipso-protiodeauration. Subsequent dissociation of the triflate ligand in this carbene in polar media due to efficient solvation of charged intermediates facilitates formation of the 1,2-Si shift products. The above results of the DFT calculations were validated by the experimental data. The present study demonstrates that DFT calculations could efficiently support experimental results, providing guidance for rational design of new catalytic transformations.
Co-reporter:Yuanzhi Xia, Alexander S. Dudnik, Yahong Li, and Vladimir Gevorgyan
Organic Letters 2010 Volume 12(Issue 23) pp:5538-5541
Publication Date(Web):November 11, 2010
DOI:10.1021/ol1024794
A mechanism of the Au-catalyzed cycloisomerization of propargylpyridines has been investigated. Both DFT computational and experimental results strongly support generation of a Au-carbene via a cyclization/proton transfer sequence over the previously proposed path involving a Au-vinylidene intermediate. For the β-Si-substituted Au-carbene (G = SiR3), a 1,2-Si migration was shown to be kinetically favored over a 1,2-H shift. This study highlights the importance of alternative pathways that could explain reactivities commonly attributed to an alkyne−vinylidene isomerization in Au catalysis.
Co-reporter:Suyun Zhang, Lina Zhen, Bin Xu, Ross Inglis, Kai Li, Wenqian Chen, Yong Zhang, Konstantis F. Konidaris, Spyros P. Perlepes, Euan K. Brechin and Yahong Li
Dalton Transactions 2010 vol. 39(Issue 15) pp:3563-3571
Publication Date(Web):14 Jan 2010
DOI:10.1039/B922672A
The employment of 2-pyridinealdoxime, (py)C(H)NOH, in nickel(II) and manganese(II) carboxylate chemistry under solvothermal conditions is reported. The syntheses, crystal structures and magnetochemical characterization (for two representative compounds) are described for [Ni6(O2CMe)6{(py)C(H)NO}6]·H2O (1·H2O), [Ni6(O2CPh)6{(py)C(H)NO}6]·2EtOH (2·2EtOH), [Ni6{(4-Cl)O2CPh}6{(py)C(H)NO}6]·2EtOH (3·2EtOH) and [Mn6(O2CMe)6{(py)C(H)NO}6]·H2O (4·H2O), where (4-Cl)PhCO2− is 4-chlorobenzoate. The reactions of M(O2CMe)2·4H2O (M = Ni, Mn) with one equivalent of (py)C(H)NOH in EtOH at 120 °C under autogenous pressure give isostructural 1·H2O and 4·H2O. Complexes 2·2EtOH and 3·2EtOH were obtained from the 1:1:1 Ni(O2CMe)2·4H2O/{(py)C(H)NOH/(X)PhCO2H reaction mixtures in EtOH under solvothermal conditions (X = H, 4-Cl). The structurally similar clusters 1–4 have a wheel-like topology with the six metal ions in a chair conformation. Each metal site is bound to four oxygen and two nitrogen atoms; the donor atoms come from two carboxylate oxygens, two oximate oxygens, one pyridyl nitrogen and one oximate nitrogen atom. The carboxylate ligands show the syn, synη1:η1:μ mode, while the (py)C(H)NO− ions behave as η1:η1:η2:μ3 ligands. Each metal⋯metal vector is bridged by one carboxylate group, one μ-O derived from a (py)C(H)NO− ligand and by one diatomic oximate–NO– group from an adjacent (py)C(H)NO− group. The IR spectra of the complexes are discussed in terms of the coordination modes of the ligands. Variable-temperature, solid-state dc magnetic susceptibility studies were carried out on polycrystalline samples of 1 and 4. The data in the 2.0–300 K range have been fit to a model with one J value revealing moderate (1) or weak (2) antiferromagnetic MII⋯MII exchange interactions. This work demonstrates the synthetic potential of combining (py)C(H)NOH with carboxylate ligands and the usefulness of solvothermal techniques in 3d-metal cluster chemistry.
Co-reporter:Lina Zheng, Suyun Zhang, Kai Li, Wenqian Chen, Yanmei Chen, Bin Xu, Bin Hu, Yahong Li, Wu Li
Journal of Molecular Structure 2010 Volume 984(1–3) pp:153-156
Publication Date(Web):15 December 2010
DOI:10.1016/j.molstruc.2010.09.020
A complex of the composition [Ni2(Hpyco)2(epa)(EtOH)Cl3] (1) (Hpyco = pyridine-2-carbaldehyde oxime; Hepa = 3-(ethoxycarbonyl)picolinic acid) has been synthesized via solvothermal synthetic reaction, and fully characterized by X-ray single crystal diffraction, IR and elemental analysis. Crystal structure revealed that 1 contains carboxylic oxygen atom bridged and chloro bridged dinuclear core with each Ni(II) exhibiting pseudo-octahedral geometry. An ester was formed in situ by the reaction of solvent ethanol with one carboxylic group of pyridine-2,3-dicarboxylic acid. Low-temperature magnetic susceptibility measurement for the solid sample of 1 revealed the ferromagnetic NiII⋯NiII interactions.
Co-reporter:Su-Yun Zhang, Yahong Li, Wu Li
Inorganica Chimica Acta 2009 Volume 362(Issue 7) pp:2247-2252
Publication Date(Web):15 May 2009
DOI:10.1016/j.ica.2008.10.010
Three complexes of composition [Co3(Hdcp)2(phen)3(H2O)2]n · nH2O (1), [Ni2(Hdcp)2(H2O)4](Im)2 (2) and [Cu2(Hpca)2(H2O)2(Im)2] (3) (H3dcp = 3,5-pyrazoledicarboxylic acid, H2pca = 1H-pyrazole-5-carboxylic acid, Im = imidazole and phen = 1,10-phenanthroline) have been synthesized via hydrothermal reactions and their structures have been characterized. Complex 1 is mainly constructed by Hdcp and ancillary ligand 1,10-phenanthroline and exhibits one-dimensional linear chain structure. Complexes 2 and 3 are pyrazolato-bridged dinuclear complexes. The ancillary imidazole ligand was not involved in the coordination and stacked to the lattice of the complex in 2. In the process of synthesis 3, imidazole ligand was coordinated to the metal centre; with one of the carboxylic group of the H3dcp ligand was eliminated to form [Cu2(Hpca)2(H2O)2(Im)2] (3) in situ. The results of magnetic susceptibility measurements indicate that there exist antiferromagnetic interactions between Co(II) and Ni(II) centres in compounds 1 and 2, respectively.Three complexes of composition [Co3(Hdcp)2(phen)3(H2O)2]n · nH2O (1), [Ni2(Hdcp)2(H2O)4](Im)2 (2) and [Cu2(Hpca)2(H2O)2(Im)2] (3) have been synthesized via hydrothermal reactions and their structures have been characterized. Complex 1 exhibits one-dimensional linear chain structure. Complexes 2 and 3 are pyrazolato-bridged dinuclear complexes. The results of magnetic susceptibility measurements indicate that there exist antiferromagnetic interactions between Co(II) and Ni(II) centres in compounds 1 and 2, respectively.
Co-reporter:Genping Huang, Yuanzhi Xia, Yahong Li
Journal of Molecular Structure: THEOCHEM 2009 Volume 896(1–3) pp:80-84
Publication Date(Web):28 February 2009
DOI:10.1016/j.theochem.2008.11.003
Substituent effects on the conformational and energetic properties of keto–enol tautomerism of monochalcogenocarboxylic acids XC(O)YH (X = H, F, NH2, OH, CN, and CH3; Y = S, Se, and Te) were investigated systematically by theoretical calculations. The relative stabilities of the tautomers, associated barrier heights and transition state geometries were reported. Results from different levels of calculations show that the keto forms are thermodynamically more stable than the enol forms by over 3 kcal/mol. Generally, compared with the H-substituted systems, the relative energies between the keto and enol isomers and activation energies of the keto–enol isomerizations are not affected much by the substituents NH2, CN, and CH3, which could form conjugations with the CO group of the keto forms or the CY moieties of the transition states and enol forms. However, both the relative energies and activation energies would be increased by the strong electron-withdrawing substituents OH and F. The factors that influence the kinetic and thermodynamic properties of the tautomerizations were analyzed. Analysis of the transition state geometries show all these 1,3-H shift transition states are more similar to the products than the reactants, and the F- and OH-substituted ones are later than others.
Co-reporter:Yuanzhi Xia, Fengying Zhou, Yahong Li, Wu Li
Journal of Molecular Structure: THEOCHEM 2009 Volume 904(1–3) pp:69-73
Publication Date(Web):30 June 2009
DOI:10.1016/j.theochem.2009.02.033
The electronic effects of an electron-withdrawing group (exemplified by formyl group) on the kinetic and thermodynamic aspects of substituted 1,5-enyne, 1,5-diyne, and 1,2-diene-5-yne Cope rearrangements were investigated by means of DFT and CBS-QB3 calculations. The energy barriers of the formyl substituted reactions are lower than those of the unsubstituted ones almost in all cases, and the barriers will be further lowered when catalyzed by AlCl3. The most obvious electronic effect was calculated for the C-2 formyl substituted 1,5-enyne rearrangements, which have activation barriers of 27.1 and 18.1 kcal/mol, respectively, for the uncatalyzed and catalyzed reactions. The charge transfer induced by the electron-withdrawing group and stabilization of the charge by Lewis acid are responsible for the different energetic profiles. The formyl substitution will change the thermodynamic profiles of the transformations, notablely, increase the reaction enthalpies of the 1,5-diyne and 1,2-diene-5-yne rearrangements by over 5.0 kcal/mol, as result of the stabilization effect of a formyl substitution attached directly to the unsaturated moieties of the products.
Co-reporter:Xiaojuan Cheng;Yuanzhi Xia;Hua Wei;Bin Xu;Chongguang Zhang;Yahong Li;Guimin Qian;Xiaohua Zhang;Kai Li;Wu Li
European Journal of Organic Chemistry 2008 Volume 2008( Issue 11) pp:1929-1936
Publication Date(Web):
DOI:10.1002/ejoc.200701080
Abstract
Intermolecular olefin hydroamination was studied by various Lewis acids. The results of ZrCl4, FeCl3, BiCl3, and AlCl3 catalyzed reactions of norbornene with aromatic amines were compared, and BiCl3 was found to be the most effective catalyst to give high yields for various amines, whereas ZrCl4 could promote the reactions at relatively low temperatures. The FeCl3 catalyzed reactions were the most chemoselective and excellent yields could be achieved for certain amines by using AlCl3. A carbocation mechanism was proposed, and the controllable syntheses of allylamine and tetrahydroquinoline from isoprene and 2,5-dichloroaniline were achieved by application of this mechanism. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Co-reporter:Jing-Wen Ran, Su-Yun Zhang, Bin Hu, Bin Xu, Yahong Li
Inorganic Chemistry Communications 2008 Volume 11(Issue 12) pp:1474-1477
Publication Date(Web):December 2008
DOI:10.1016/j.inoche.2008.10.013
[Ni3(pymp)4(pya)2](NO3)2(CH3OH)2 (1), [Ni3(pymp)4(pya)2]Cl2(CH3OH)2 (2) and [Ni(pymp)2(py)2] (3) (Hpymp = 2-[(pyridine-2-ylimine)methyl]phenol, pya = pyridin-2-amine and py = pyridine) were synthesized and characterized. Crystal structures reveal that 1 and 2 contain phenoxo-bridged and N–C–N bridged linear trinuclear cores (uncommon for trinuclear nickel complexes), with the central Ni(II) being coordinated in a NiO4N2 fashion while the two terminal Ni(II) atoms adopt a NiO2N4 coordination mode. Two novel coordination modes of Hpymp ligand are presented in 1 and 2. Complex 3 displays a NiO2N4 coordination mode with the Ni(II) in a slightly distorted octahedral environment. Magnetic measurements of 1 indicated that the Ni centers are ferromagnetically coupled.[Ni3(pymp)4(pya)2](NO3)2(CH3OH)2 (1), [Ni3(pymp)4(pya)2]Cl2(CH3OH)2 (2) and [Ni(pymp)2(py)2] (3) (Hpymp = 2-[(pyridine-2-ylimine)methyl]phenol, pya = pyridin-2-amine and py = pyridine) were synthesized and characterized. Crystal structures reveal that 1 and 2 contain phenoxo-bridged and N–C–N bridged linear trinuclear cores (uncommon for trinuclear nickel complexes), with the central Ni(II) being coordinated in a NiO4N2 fashion while the two terminal Ni(II) atoms adopt a NiO2N4 coordination mode. Two novel coordination modes of Hpymp ligand are presented in 1 and 2. Complex 3 displays a NiO2N4 coordination mode with the Ni(II) in a slightly distorted octahedral environment. Magnetic measurements of 1 indicated that the Ni centers are ferromagnetically coupled.
Co-reporter:Guimin Qian;Yuanzhi Xia;Hua Wei;Wu Li;Yahong Li;Kai Li
European Journal of Organic Chemistry 2007 Volume 2007(Issue 27) pp:4471-4474
Publication Date(Web):30 JUL 2007
DOI:10.1002/ejoc.200700483
A BiCl3-catalyzed hydroamination reaction of norbornene, in which a variety of electron-withdrawing groups were tolerated on amines, was presented. The current transformation possesses the advantages of being highly selective, cheap, and eco-friendly, and this process also represents a rare system for main-group Lewis acid catalyzed intermolecular hydroamination of unactivated alkenes.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Co-reporter:Xiao-Yu Han;Hua Wei;Yong Zhang
Chinese Journal of Chemistry 2007 Volume 25(Issue 9) pp:1334-1339
Publication Date(Web):17 SEP 2007
DOI:10.1002/cjoc.200790248
Two ligand bridged binuclear titanium complexes Ti2(bppda)3(NMe2)2·3THF (1) and Ti2(bppda)3(NEt2)2·3THF (2) and one bis-ligand coordinated mononuclear complex Ti(bppda)2 (3) (ligand: H2bppdaN,N′-Bis(2-pyrrylmeth-ylidene)-1,2-phenylenediamine) were synthesized by adjusting the ratio of the starting materials and the reaction speed. The complexes were fully characterized with NMR, elemental analysis and X-ray crystal diffraction. The catalytic activity of the complex 1 to phenylacetylene hydroanilination reaction was also investigated.
Co-reporter:Li Ya-Hong;Song Peng-Sheng;Xia Shu-Ping;Li Wu;Gao Shi-Yang
Chinese Journal of Chemistry 2005 Volume 23(Issue 8) pp:
Publication Date(Web):10 OCT 2005
DOI:10.1002/cjoc.200590953
Component solubility in HCl-LiCl-MgCl2-H2O system of high ionic strength at 20 °C was predicted by using the Pitzer's ion-interaction model. The results indicated that the model supplied a very good prediction of the component solubility of the system mentioned above. The values of parameters of β0, β1 and Cϕ of HCl, LiCl and MgCl2 were obtained from optimization of literature data, while those of θMN and ψMNX were calculated from a least-squares optimization procedure to couple activity coefficient with solubility data. According to the ion-interaction model, no additional parameters need to be determined for more complex systems. The study provided theoretical basis for the manufacture process, which was proposed by Gao and employed to extract LiCl and MgCl2·6H2O from salt lake brine.
Co-reporter:Hao Sun, Jin Zhang, Yanping Cai, Wei Liu, Xiangfei Zhang, Yaping Dong, Yahong Li
Polyhedron (29 March 2017) Volume 125() pp:
Publication Date(Web):29 March 2017
DOI:10.1016/j.poly.2016.10.025
The employment of a tridentate Schiff base ligand, 1-(((2-hydroxy-2,3-dihydro-1H-inden-1-yl)imino)methyl)naphthalen-2-ol (H2L) in the coordination chemistry of cobalt(II) acetate and copper(II) acetate is reported. One cubane-like cluster of formula [Co4L4]·CH3OH (1·CH3OH) and one alkoxo-bridged dinuclear copper compound of composition [Cu2L2] (2) were achieved by the reactions of metal acetates with H2L under solvothermal conditions. The structures of 1·CH3OH and 2 have been established by single-crystal X-ray diffraction studies. Complex 1·CH3OH has a cubane-like {Co4O4} core with divalent metal atoms and alkoxo atoms (originated from the L2− ligands) occupying alternating vertices. The magnetic properties of 1·CH3OH and 2 have been investigated. The variable-temperature dc magnetic susceptibility studies indicate ferromagnetic CoII⋯CoII exchange interactions for 1·CH3OH and antiferromagnetic CuII⋯CuII couplings for 2. The ac magnetic susceptibility investigation reveals that complex 1·CH3OH shows the slow magnetic relaxation (SMM) behavior.One cubane-type {Co4O4} cluster and a dinuclear copper compound were synthesized and characterized; complex 1 shows SMM behavior.
Co-reporter:Shixiong She, Yahong Li and Wu Li
Dalton Transactions 2016 - vol. 45(Issue 26) pp:NaN10835-10835
Publication Date(Web):2016/06/06
DOI:10.1039/C6DT00951D
Two new 3d–4f heterometallic 1D chains of formulae {[Dy2M2L4(NO3)(H2O)3][Dy2M2L4(NO3)(CH3COO)(H2O)2]·NO3·12H2O·2C2H5OH}n [M = Ni (1); Co (2)] have been prepared using the multidentate ligand 2-{[(2-hydroxy-3-methoxyphenyl)methylidene]amino}benzoic acid (H2L), which has NO and OO′ chelating pockets that are able to selectively encapsulate LnIII and transition metal ions, respectively. Crystal structure analyses reveal that the two complexes are isostructural and display one-dimensional ladder-like double helical chain structures, in which the two single helical chains {[Dy2M2L4(NO3)(H2O)3]+} and {Dy2M2L4(NO3)(CH3COO)(H2O)2} (M = Ni(1), Co(2)) both run along the c-axis and have opposite chirality. Complexes 1 and 2 represent the first example of 3d–4f double-chain frameworks in which the compositions of the two individual chains are different. Variable temperature dc magnetic susceptibility studies reveal different strengths of ferromagnetic interactions between the magnetic centers in 1 and 2, which is mainly attributed to the different metal centers and finally results in the distinctive magnetic dynamic behaviors.
Co-reporter:Yanmei Chen, Yanyuan Cao, Wenqian Chen, Qian Gao, Lei Li, Dandan Gao, Wei Liu, Yahong Li and Wu Li
Dalton Transactions 2013 - vol. 42(Issue 27) pp:NaN10018-10018
Publication Date(Web):2013/05/09
DOI:10.1039/C3DT50453K
The employment of pyridine-2,6-dicarboxylic acid (H2pda) and imidazole (im) in the synthesis of SrII–SmIII and SrII–DyIII coordination polymers has been reported. Seven novel heterometallic coordination polymers of compositions, [Dy3Sr3(pda)7(Hpda)(H2O)9]·6H2O (1), [LnSr(pda)3(H2O)5]·Him·H2O (Ln = Sm(2), Dy(3)), [Ln2Sr(pda)6(H2O)5]·4Him·C2H5OH·nH2O (Ln = Sm(4), n = 4; Dy(5), n = 5), [Sm2Sr2(pda)5(H2O)9]·2H2O (6) and [DySr(pda)3(H2O)4]·Him·3H2O (7), have been prepared and characterized. Complexes 1, 2–3, and 6 display three varieties of 2-D structures. 4–5 and 7 exhibit two types of 1-D chain structures. The structures of the complexes could be controlled via choosing appropriate starting materials and tuning the amount of imidazole. The photo-luminescent properties of these complexes have been investigated. The results show the exclusive luminescence emission bands being characteristic of SmIII and DyIII.
Co-reporter:Shixiong She, Yanmei Chen, Michael J. Zaworotko, Wei Liu, Yanyuan Cao, Jian Wu and Yahong Li
Dalton Transactions 2013 - vol. 42(Issue 29) pp:NaN10438-10438
Publication Date(Web):2013/05/09
DOI:10.1039/C3DT50417D
A new family of octanuclear lanthanide compounds [Na2Ln6L8(C6H4NH2COO)2(C2H5OH)2(H2O)4(NO3)]·NO3·C2H5OH·nH2O [H2L = 2-{[(2-hydroxy-3-methoxyphenyl)methylidene]amino}benzoic acid; Ln = Dy (1) (n = 15); Tb (2), Gd (3) (n = 14); Sm (4) (n = 16)] have been prepared under hydrothermal conditions. The X-ray crystal structure analysis reveals that complexes 1–4 are isomorphous. The core of the structure is a [4 + 2] combination of an Ln4 cubane and an Ln2 unit. The two units are bridged by a nitrate ion, which is located in the center of the cluster and displays an unusual μ8-η2:η2:η4 tridentate bridging mode. The magnetic studies for complex 1 show that the [Na2Dy6] unit exhibits slow magnetic relaxation behavior.
Co-reporter:Yanmei Chen, Wenqian Chen, Zhenghua Ju, Qian Gao, Tao Lei, Wei Liu, Yahong Li, Dandan Gao and Wu Li
Dalton Transactions 2013 - vol. 42(Issue 29) pp:NaN10502-10502
Publication Date(Web):2013/05/22
DOI:10.1039/C3DT51184G
Eight novel SrII–LnIII heteronuclear coordination polymers based on pyridine-2,6-dicarboxylic acid (H2pda) and imidazole (im) ligands, namely, [LnSr(pda)3(H2O)5]·Him·H2O (Ln = Eu (1), Gd (2), Tb (3)), [Ln2Sr(pda)6(H2O)5]·4Him·C2H5OH·nH2O (Ln = Eu (4), n = 5; Gd (5), n = 4), [LnSr(pda)3(H2O)4]·Him·3H2O (Ln = Gd (6), Tb (7)), and [GdSr(pda)3(H2O)5]·Him·C2H5OH·3H2O (8), have been prepared by employing different amounts of imidazole. X-ray crystal structure analysis reveals that these compounds exhibit a rich structural chemistry. Complexes 1–3 possess 2-D frameworks. Complexes 4–5, 6–7, and 8 exhibit three types of 1-D chain structure. The structures of the complexes could be rationally tuned via adding different amounts of imidazole. The luminescent properties of these complexes have been investigated. The results show that EuIII and TbIII complexes exhibit intense red and green luminescence emission which are characteristics of TbIII and EuIII, respectively. Solid-state quantum yield and the lifetime of these complexes are also reported.
Co-reporter:Yanmei Chen, Lina Zheng, Shixiong She, Zhou Chen, Bin Hu and Yahong Li
Dalton Transactions 2011 - vol. 40(Issue 18) pp:NaN4975-4975
Publication Date(Web):2011/03/21
DOI:10.1039/C1DT10034C
The syntheses, crystal structures and magnetic properties are described for two novel 2D heterometallic CuII-SrII coordination polymers {Sr(H2O)6[(Im)4Cu4(pdc)4Sr(H2O)4]·6H2O}n (1) and [Cu2(H2O)2(pdc)2Sr(H2O)3]n (2) (H3pdc = 3,5-pyrazoledicarboxylic acid; Im = imidazole). The 1:1:1:5 reaction of SrCl2·6H2O, Cu(NO3)2·3H2O, H3pdc and imidazole in H2O–EtOH at 120 °C under autogenous pressure gave 1. Complex 2 was obtained from the 1:1:1 H3pdc/Sr(OH)2·8H2O/Cu(NO3)2·3H2O reaction mixture in H2O–EtOH under solvothermal conditions. Complex 1 can be described as a 2D grid-shaped network with the four CuII ions in a saddle-like conformation. In complex 2, SrII ions link metalloligands [Cu2(pdc)2(H2O)2]2− to generate a 2D layer framework. Variable-temperature solid-state dc magnetic susceptibility studies have been performed in the temperature range 2.0–300 K for complexes 1 and 2. Antiferromagnetic CuII⋯CuII exchange interactions were found for both 1 and 2.
Co-reporter:Suyun Zhang, Lina Zhen, Bin Xu, Ross Inglis, Kai Li, Wenqian Chen, Yong Zhang, Konstantis F. Konidaris, Spyros P. Perlepes, Euan K. Brechin and Yahong Li
Dalton Transactions 2010 - vol. 39(Issue 15) pp:NaN3571-3571
Publication Date(Web):2010/01/14
DOI:10.1039/B922672A
The employment of 2-pyridinealdoxime, (py)C(H)NOH, in nickel(II) and manganese(II) carboxylate chemistry under solvothermal conditions is reported. The syntheses, crystal structures and magnetochemical characterization (for two representative compounds) are described for [Ni6(O2CMe)6{(py)C(H)NO}6]·H2O (1·H2O), [Ni6(O2CPh)6{(py)C(H)NO}6]·2EtOH (2·2EtOH), [Ni6{(4-Cl)O2CPh}6{(py)C(H)NO}6]·2EtOH (3·2EtOH) and [Mn6(O2CMe)6{(py)C(H)NO}6]·H2O (4·H2O), where (4-Cl)PhCO2− is 4-chlorobenzoate. The reactions of M(O2CMe)2·4H2O (M = Ni, Mn) with one equivalent of (py)C(H)NOH in EtOH at 120 °C under autogenous pressure give isostructural 1·H2O and 4·H2O. Complexes 2·2EtOH and 3·2EtOH were obtained from the 1:1:1 Ni(O2CMe)2·4H2O/{(py)C(H)NOH/(X)PhCO2H reaction mixtures in EtOH under solvothermal conditions (X = H, 4-Cl). The structurally similar clusters 1–4 have a wheel-like topology with the six metal ions in a chair conformation. Each metal site is bound to four oxygen and two nitrogen atoms; the donor atoms come from two carboxylate oxygens, two oximate oxygens, one pyridyl nitrogen and one oximate nitrogen atom. The carboxylate ligands show the syn, synη1:η1:μ mode, while the (py)C(H)NO− ions behave as η1:η1:η2:μ3 ligands. Each metal⋯metal vector is bridged by one carboxylate group, one μ-O derived from a (py)C(H)NO− ligand and by one diatomic oximate–NO– group from an adjacent (py)C(H)NO− group. The IR spectra of the complexes are discussed in terms of the coordination modes of the ligands. Variable-temperature, solid-state dc magnetic susceptibility studies were carried out on polycrystalline samples of 1 and 4. The data in the 2.0–300 K range have been fit to a model with one J value revealing moderate (1) or weak (2) antiferromagnetic MII⋯MII exchange interactions. This work demonstrates the synthetic potential of combining (py)C(H)NOH with carboxylate ligands and the usefulness of solvothermal techniques in 3d-metal cluster chemistry.
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