Co-reporter:Jia Li; Hong-Ru Fu; Jian Zhang; Lan-Sun Zheng
Inorganic Chemistry 2015 Volume 54(Issue 7) pp:3093-3095
Publication Date(Web):March 24, 2015
DOI:10.1021/acs.inorgchem.5b00316
The reaction of nickel(II) sulfate with 4,4′,4″-s-triazine-2,4,6-triyltribenzoate in dimethyl sulfoxide afforded a hexanuclear nickel(II)-based anionic 2-fold interpenetrated metal–organic framework exhibiting the ability to adsorb and separate light hydrocarbons and canted antiferromagnetism.
Co-reporter:Xue-Ru Wu, Hai-Yan Shi, Rong-Jia Wei, Jia Li, Lan-Sun Zheng, and Jun Tao
Inorganic Chemistry 2015 Volume 54(Issue 8) pp:3773-3780
Publication Date(Web):March 30, 2015
DOI:10.1021/ic5029542
The self-assemblies of 1,4-bis(pyrid-4-yl)benzene (bpb) and Fe(NCX)2 (X = S, Se, BH3) afforded six coordination polymers with the general formula of [Fe(bpb)2(NCX)2]·Y (X = S and Y = 3C2H5OH·2.5H2O for complex 4, X = S and Y = 2C2H5OH for 5, X = Se and Y = 2C2H5OH·H2O for 6, X = Se and Y = 0.67CH2Cl2·1.33C2H5OH·0.67H2O for 7, X = BH3 and Y = 3C2H5OH·2H2O for 8, X = BH3 and Y = 2CH2Cl2·2C2H5OH for 9). The frameworks of complexes 4 and 5 with the NCS– anion as coligand are supramolecular isomers, of which complex 4 features a threefold self-interpenetrated three-dimensional (3D) CdSO4-type topological structure with a Schläfli symbol of 65·8, and complex 5 is a two-dimensional (2D) 44 rhombic grid network. These two complexes are purely high-spin systems. Complexes 6 and 7 with the NCSe– anion as coligand, both having the 3D 65·8 CdSO4-type framework, show gradual and incomplete spin-crossover behaviors with transition temperature T1/2 being equal to 86 and 96 K, respectively. The usage of NCBH3– anion as coligand leads to the formation of 2D 44 rhombic grid networks for both complexes 8 and 9, which undergo relatively abrupt, complete spin crossover with T1/2 being equal to 247 and 189 K, respectively. The structural divergences are attributed to the coligands NCX– (X = S, Se, BH3) and solvent molecules. Meanwhile, a significant coligand effect is observed on the spin-crossover behaviors of these complexes, and the completeness and transition temperature of spin-state conversion depends on the nature of the coligand, that is, T1/2(NCS–) < T1/2(NCSe–) < T1/2(NCBH3–). These results further facilitate the design and synthesis of spin-crossover complexes with spin-state conversion.
Co-reporter:Ying Guo; Xiu-Long Yang; Rong-Jia Wei; Lan-Sun Zheng
Inorganic Chemistry 2015 Volume 54(Issue 16) pp:7670-7672
Publication Date(Web):July 29, 2015
DOI:10.1021/acs.inorgchem.5b01344
A mononuclear compound, [CoII(pyterpy)2](PF6)2·2CH3OH [2; pyterpy = 4′-(4‴-pyridyl)-2,2′:6′,2″-terpyridine], shows a phase-transition-coupled, abrupt spin transition with a 9 K wide hysteresis that can transform to a spin-crossover compound, [CoII(pyterpy)2](PF6)2·2CH2Cl2·CH3OH (3).
Co-reporter:Chun-Feng Wang;Dr. Ren-Fu Li;Dr. Xue-Yuan Chen;Dr. Rong-Jia Wei;Dr. Lan-Sun Zheng;Dr. Jun Tao
Angewandte Chemie 2015 Volume 127( Issue 5) pp:1594-1597
Publication Date(Web):
DOI:10.1002/ange.201410454
Abstract
Hybrid materials integrated with a variety of physical properties, such as spin crossover (SCO) and fluorescence, may show synergetic effects that find applications in many fields. Herein we demonstrate a promising post-synthetic approach to achieve such materials by grafting fluorophores (1-pyrenecarboxaldehyde and Rhodamine B) on one-dimensional SCO FeII structures. The resulting hybrid materials display expected one-step SCO behavior and fluorescent properties, in particular showing a coupling between the transition temperature of SCO and the temperature where the fluorescent intensity reverses. Consequently, synergetic effect between SCO and fluorescence is incorporated into materials despite different fluorophores. This study provides an effective strategy for the design and development of novel magnetic and optical materials.
Co-reporter:Chun-Feng Wang;Dr. Ren-Fu Li;Dr. Xue-Yuan Chen;Dr. Rong-Jia Wei;Dr. Lan-Sun Zheng;Dr. Jun Tao
Angewandte Chemie International Edition 2015 Volume 54( Issue 5) pp:1574-1577
Publication Date(Web):
DOI:10.1002/anie.201410454
Abstract
Hybrid materials integrated with a variety of physical properties, such as spin crossover (SCO) and fluorescence, may show synergetic effects that find applications in many fields. Herein we demonstrate a promising post-synthetic approach to achieve such materials by grafting fluorophores (1-pyrenecarboxaldehyde and Rhodamine B) on one-dimensional SCO FeII structures. The resulting hybrid materials display expected one-step SCO behavior and fluorescent properties, in particular showing a coupling between the transition temperature of SCO and the temperature where the fluorescent intensity reverses. Consequently, synergetic effect between SCO and fluorescence is incorporated into materials despite different fluorophores. This study provides an effective strategy for the design and development of novel magnetic and optical materials.
Co-reporter:Jia Li, Ying Guo, Hong-Ru Fu, Jian Zhang, Rong-Bin Huang, Lan-Sun Zheng and Jun Tao
Chemical Communications 2014 vol. 50(Issue 65) pp:9161-9164
Publication Date(Web):27 Jun 2014
DOI:10.1039/C4CC02396J
The reaction of nickel(II) nitrate with isonicotinic acid and 2,6-dimethyl-pyridine-3,5-dicarboxylic acid affords a novel, tetranuclear nickel(II)-based metal–organic framework that exhibits spin-canted antiferromagnetism with a canted angle of 1.65° and high adsorptive selectivity for light hydrocarbons.
Co-reporter:Xiang-Yi Chen, Rong-Jia Wei, Lan-Sun Zheng, and Jun Tao
Inorganic Chemistry 2014 Volume 53(Issue 24) pp:13212-13219
Publication Date(Web):November 25, 2014
DOI:10.1021/ic502471v
Three novel complexes, namely, [CoIII(3,5-DBCat)(3,5-DBSq)(bpe)]·2CH3CN·2H2O (1·S), [CoIII(3,5-DBCat)(3,5-DBSq)(azpy)]·2CH3CN·2H2O (2·S), and [CoII(3,5-DBSq)2(bpb)][CoIII(3,5-DBCat)(3,5-DBSq)(bpb)]0.5·2CH3CN·2H2O (3·S), were synthesized and characterized by valence tautomeric (VT) X-ray diffraction and magnetic measurements [where 3,5-DBCatH2 = 3,5-di-tert-butyl-catechol, 3,5-DBSqH = 3,5-di-tert-butyl-semiquinone, bpe = trans-bis(4-pyridyl)ethylene, azpy = trans-4,4′-azopyridine, and bpb = 1,4-bis(4-pyridyl)benzene]. The three complexes have similar one-dimensional chain structure building from bidentate-bridging pyridine ligands and planar 3,5-DBCat/3,5-DBSq-fixed CoII/III entities. Complexes 1·S and 2·S could retain the crystallinity during desolvation, and the crystal structures of 1 and 2 were therefore able to be determined. Only when 1·S and 2·S desolvated above 310 K did the magnetic susceptibilities × temperatures values of the two complexes rise sharply, and then thermally induced complete, one-step VT transitions for 1 and 2 were available and repeatable. Complex 3·S showed an incomplete, one-step VT transition independent of solvent molecules. Among these complexes, only 1 was sensitive to photoexcitation at low temperature, its photoinduced metastable state relaxed with temperature-independent behavior at low temperature range (5–10 K) and with thermally assisted behavior at high temperature range (above 20 K), respectively.
Co-reporter:Xiang-Yi Chen, Rong-Bin Huang, Lan-Sun Zheng, and Jun Tao
Inorganic Chemistry 2014 Volume 53(Issue 10) pp:5246-5252
Publication Date(Web):April 29, 2014
DOI:10.1021/ic500463m
In our previous work (Chen, X.-Y.; Chem. Commun. 2013, 49, 10977−10979), we have reported the crystal structure and spin-crossover properties of a compound [Fe(NCS)2(tppm)]·S [1·S, tppm = 4,4′,4″,4‴-tetrakis(4-pyridylethen-2-yl)tetraphenylmethane, S = 5CH3OH·2CH2Cl2]. Here, its analogues [Fe(X)2(tppm)]·S [X = NCSe–, NCBH3–, and N(CN)2– for compounds 2·S, 3·S, and 4·S, respectively] have been synthesized and characterized by variable-temperature X-ray diffraction and magnetic measurements. The crystal structure analyses of 2·S and 3·S reveal that both compounds possess the same topologic framework (PtS-type) building from the tetrahedral ligand tppm and planar unit FeX2; the framework is two-fold self-interpenetrated to achieve one-dimensional open channels occupied by solvent molecules. Powder X-ray diffraction study indicates the same crystal structure for 4. The average values of Fe–N distances observed, respectively, at 100, 155, and 220 K for the Fe1/Fe2 centers are 1.969/2.011, 1.970/2.052, and 2.098/2.136 Å for 2·S, whereas those at 110, 175, and 220 K are 1.972/2.013, 1.974/2.056, and 2.100/2.150 Å for 3·S, indicating the presence of a two-step spin crossover in both compounds. Temperature-dependent magnetic susceptibilities (χMT) confirm the two-step spin-crossover behavior at 124 and 200 K in 2·S, 151 and 225 K in 3·S, and 51 and 126 K in 4·S, respectively. The frameworks of 2–4 are reproducible upon solvent exchange and thereafter undergo solvent-dependent spin-crossover behaviors.
Co-reporter:Xue-Ru Wu, Xü Yang, Rong-Jia Wei, Jia Li, Lan-Sun Zheng, and Jun Tao
Crystal Growth & Design 2014 Volume 14(Issue 10) pp:4891-4894
Publication Date(Web):September 11, 2014
DOI:10.1021/cg5011506
The assembly of 1,4-bis(pyrid-4-yl)benzene (bpb) and Fe(NCS)2 affords three supramolecular isomeric frameworks formulated as [Fe(bpb)2(NCS)2]·X (X = 3EtOH for 1, 2.5H2O for 2, and 0 for 3, respectively). Crystallographic studies reveal that 1 belongs to the monoclinic space group C2/c and crystallizes into a threefold self-interpenetrated 3D 65·8 CdSO4-type framework, whereas 2 crystallizes in the monoclinic space group P2/c and features a 2D 44 square-grid network. The immersion of red crystals of 1 into a methanol/ethanol (1:3) solvent led to the formation of yellow crystals of 3, showing structural transformation via crystal disassembly and reassembly process. 3 crystallizes in the triclinic space group P1̅ and is a 2D 44 rhombus-grid network, but showing nonporous feature (compared with 2) because of more compact network stacking. The most interesting feature is that crystals of 3 are not able to be synthesized by the direct reaction of Fe(NCS)2 with ligand bpb. We suppose that this structural isomerization is a solvent-mediated rearrangement of coordination bonds from a kinetically favored isomer (1) to the thermodynamically stable form (3) of the system. It is generally believed that the framework of higher dimensionality is a more stable phase than that of lower dimensionality. While conversions between supramolecular isomers from 1D to 2D, 1D to 3D, and 2D to 3D have been observed, examples showing 3D to 2D or 3D to 1D isomerization are rarely reported. The structural transformation herein represents a rather scarce case from higher dimensional framework (3D) to lower one (2D).
Co-reporter:Jia Li, Peng Huang, Xue-Ru Wu, Jun Tao, Rong-Bin Huang and Lan-Sun Zheng
Chemical Science 2013 vol. 4(Issue 8) pp:3232-3238
Publication Date(Web):28 May 2013
DOI:10.1039/C3SC51379C
Three metal-organic frameworks (MOFs) formulated as [Co3O(BTB)2(H2O)x(DMF)y]·zDMF·nH2O (BTB = 1,3,5-benzenetribenzoate; 1a, x = y = 1, z = 7.5, n = 12; 1b, x = 2, y = 0, z = 8.5, n = 8; 1c, x = 2, y = 1, z = 7, n = 8) have been synthesized under different temperatures; they crystallize as two-fold interpenetrated analogous structures with the same structural trinuclear Co3O(CO2)6 secondary building units (SBUs), and their stabilities depend on the temperature under which they formed. Upon immersion in the filtrate of 1a (namely 1a-s, freshly filtered) or 1b (namely 1b-s, filtered and then activated in air for three days), single crystal-to-single crystal (SCSC) transformations of 1a–1c to a new MOF, formulated as [Co6O2(OH)4(BTB)8/3(H2O)4]·14DMF·4EtOH·2H2O (2), occur along with dramatic color change from blue purple to red. Crystallographic studies reveal that the new MOF is also two-fold interpenetrated but is constructed with hexanuclear Co6O2(CO2)8 SBUs. This SCSC transformation from 1a–1c to 2 can take place only in 1a-s or 1b-s but not in 1c-s and is accompanied with an increase of metal-to-ligand ratio. ESI-MS studies unveil the formation of free {Co3O} units in situ formed only in 1a-s and 1b-s, and evidence that the SCSC transformation involves a postsynthetic uptake of free metal clusters, {Co3O}. On the other hand, the SCSC transformation speed decreases from 1a to 1c, which is determined by the chelate carboxylate groups undergoing cleavage of metal-carboxylate bonds during the SCSC transformation and the shape of the 1D channels affecting the diffusion of free metal clusters. Furthermore, the resulting MOF (2) can maintain its crystallinity upon activation and adsorbs iodine up to 38 wt%. Combined with the significant SCSC transformation through postsynthetic uptake of free metal clusters and the resulting MOF capable of adsorbing iodine, the present approach not only provides a true route to construct SBUs-based MOF materials with pre-existing “real” SBUs but also represent a new type of SCSC transformation in the field of MOFs that is able to efficiently tune structures and physicochemical properties of MOFs in the solid states.
Co-reporter:Xiang-Yi Chen, Hai-Yan Shi, Rong-Bin Huang, Lan-Sun Zheng and Jun Tao
Chemical Communications 2013 vol. 49(Issue 93) pp:10977-10979
Publication Date(Web):07 Oct 2013
DOI:10.1039/C3CC45691A
A 3D 2-fold interpenetrated porous coordination polymer, [Fe(NCS)2(tppm)]·5CH3OH·2CH2Cl2 (1·sol, tppm = 4,4′,4′′,4′′′-tetrakis(4-pyridylethen-2-yl)tetraphenylmethane), was synthesized, which showed temperature, light and solvent-induced spin-crossover behaviours.
Co-reporter:Feng Shao, Jia Li, Jia-Ping Tong, Jian Zhang, Ming-Guang Chen, Zhiping Zheng, Rong-Bin Huang, Lan-Sun Zheng and Jun Tao
Chemical Communications 2013 vol. 49(Issue 91) pp:10730-10732
Publication Date(Web):27 Sep 2013
DOI:10.1039/C3CC45180A
A metal–organic framework, [{Fe(NCS)2}3(TPB)4]·x(guest) [1·x(guest), TPB = 1,3,5-tris(4-pyridyl)benzene], shows selective gas adsorption and guest-dependent spin-crossover behaviour.
Co-reporter:Jia Li, Bao Li, Peng Huang, Hai-Yan Shi, Rong-Bin Huang, Lan-Sun Zheng, and Jun Tao
Inorganic Chemistry 2013 Volume 52(Issue 19) pp:11573-11579
Publication Date(Web):September 25, 2013
DOI:10.1021/ic401912k
Four 3D coordination polymers, [Co7(OH)4(H2O)2(ina)4(ip)3]·10H2O (1·10H2O, ina = isonicotinate, ip = isophthalate), [Ni7(OH)4(H2O)2(ina)4(ip)3]·10H2O (2·10H2O), [Co7(OH)4(H2O)2(ina)4(pip)3]·5H2O (3·5H2O, pip = 5-phenyl-isophthalate), and [Ni7(OH)4(H2O)2(ina)4(pip)3]·5H2O (4·5H2O), respectively, were hydrothermally synthesized. They crystallized in the orthorhombic space group Pba2 for 1·10H2O and 2·10H2O and monoclinic space group P2/n for 3·5H2O and 4·5H2O, respectively, and were constructed with the identical 8-connected heptanuclear {M7(OH)4} (M = CoII or NiII) clusters, possessing uninodal hexagonal primitive net with the point symbol {36·418·53·6}. The four coordination polymers showed dominant antiferromangetic properties, in which 1·10H2O shows spin-canted behavior and 2·10H2O exhibits the coexistence of spin canting and spin glass. Meanwhile, the activated polymers 1 and 2 possessed permanent porosity, displaying relatively large H2 uptake capacity (77 K, 1 atm) of 114 and 133 cm3 g–1, and CO2 uptake capacity (273 K, 1 atm) of 65.8 and 73.3 cm3 g–1, for 1 and 2, respectively.
Co-reporter:Bao Li, Li-Qin Chen, Jun Tao, Rong-Bin Huang, and Lan-Sun Zheng
Inorganic Chemistry 2013 Volume 52(Issue 8) pp:4136-4138
Publication Date(Web):March 27, 2013
DOI:10.1021/ic4000268
A dinuclear valence tautomeric compound containing a cationic structure with crystallographically distinguishable hs-CoII and ls-CoIII centers undergoes unidirectional charge transfer.
Co-reporter:Yue-Ling Bai, Xiaoli Bao, Shourong Zhu, Jianhui Fang and Jun Tao
Dalton Transactions 2013 vol. 42(Issue 4) pp:1033-1038
Publication Date(Web):16 Oct 2012
DOI:10.1039/C2DT31944F
Two chain compounds built with anti–anti acetate bridged MnIII3O units, [Mn3O(Clppz)3(EtOH)4(OAc)]n (1) and [Mn3O(Clppz)3(EtOH)2(OAc)]n (2), were synthesized and characterized. The magnetic studies indicate that 1 is a single-chain magnet with two slow magnetization relaxation processes which has for the first time been found in this type of chain complex, while 2 shows a field-induced metamagnetic behavior. The quite different magnetic behaviors resulted from the different number of coordinated ethanol molecules on the MnIII3O unit, four ethanol molecules for 1, and two ethanol molecules for 2. The best fittings to the experimental magnetic susceptibilities gave J1 = −2.72 cm−1, J2 = −4.34 cm−1, zJ = 1.24 cm−1 for 1 and J1 = −5.91 cm−1, J2 = −0.98 cm−1, zJ = 1.71 for 2 above 30 K. The positive zJ values indicate the presence of weak ferromagnetic interactions between the trinuclear units via acetate bridges in 1 and 2.
Co-reporter:Rong-Jia Wei, ;Rong-Bin Huang ;Lan-Sun Zheng
European Journal of Inorganic Chemistry 2013 Volume 2013( Issue 5-6) pp:916-926
Publication Date(Web):
DOI:10.1002/ejic.201200541
Abstract
A series of FeII complexes based on [Fe(tpa)]2+ building units and [N(CN)2]– bridging ligands with different anions for charge balance has been prepared and characterized. They have a general formula [Fe(tpa){N(CN)2}]x·Y·Z, where x = 4 (14+), Y = 4ClO4–, and Z = 2H2O for 1·(ClO4)4(H2O)2; x = n (2n+), Z = 0, and Y = nClO4–, nPF6–, nAsF6–, and nBPh4– for 2·(ClO4)n, 2·(PF6)n, 2·(AsF6)n, and 2·(BPh4)n, respectively; x = 2 (32+), Z = 0, and Y = 2BPh4– for 3·(BPh4)2; x = 4 (44+), Y = 3SbF6– + [N(CN)2]–, and Z = [Fe(tpa){N(CN)2}2] (5) + 4H2O for (4+5). Single-crystal X-ray diffraction studies reveal that these complexes show various structures that are affected by different counteranions, i.e., square 1·(ClO4)4(H2O)2, zigzag polymers [2·(ClO4)n, 2·(PF6)n, 2·(AsF6)n, and 2·(BPh4)n], dimeric 3·(BPh4)2, and [4+1]-cocrystallized (4+5). Magnetic studies show that the square complex 1·(ClO4)4(H2O)2 undergoes a two-step complete spin crossover, whereas the dimer 3·(BPh4)2 is high-spin in the whole temperature range, and all zigzag polymer 2·anions show spin-crossover (SCO) behavior, the transition temperature (T1/2) of which increases with increasing anion size. Interestingly, complex (4+5) displays a gradual two-step spin crossover, which is different from that of 1·(ClO4)4(H2O)2 and originates from the cocrystallized spin-crossover tetranuclear and monomeric species. Detailed studies on the crystal structures and magnetic properties have unveiled a remarkable anion-dependent formation of different structures and SCO behavior of these complexes.
Co-reporter:Xi-Ling Deng, Shi-Yao Yang, Rui-Fang Jin, Jun Tao, Chao-Qing Wu, Ze-Lan Li, La-Sheng Long, Rong-Bin Huang, Lan-Sun Zheng
Polyhedron 2013 50(1) pp: 219-228
Publication Date(Web):
DOI:10.1016/j.poly.2012.10.052
Co-reporter:Jun Tao, Rong-Jia Wei, Rong-Bin Huang and Lan-Sun Zheng
Chemical Society Reviews 2012 vol. 41(Issue 2) pp:703-737
Publication Date(Web):02 Sep 2011
DOI:10.1039/C1CS15136C
The occurrence of spin-crossover (SCO) highly depends on external influences, i.e. temperature, pressure, light irradiation or magnetic field, this electronic switching phenomenon is accompanied by drastic changes in magnetic and optical properties, dielectric constants, colour and structures. Thus, SCO materials are particularly attractive for potential applications in molecular sensing, switching, data storage, display, and other electronic devices at nanometric scale. Polymorphism is widely encountered in the studies of crystallization, phase transition, materials synthesis, biomineralization, and in the manufacture of drugs. Because different crystal forms of the same substance can possess very different properties and behave as different materials, so they are particularly meaningful for investigating SCO phenomena. Studying polymorphism of SCO compounds is therefore important for better understanding the structural factors contributing to spin transition and the structure–function relationship. This critical review is aimed to provide general readers with a comprehensive view of polymorphism in SCO systems. The article is generally structured according to specific metal ions and the dimensionality of compounds in the field. This paper is addressed to readers who are interested in multifunctional materials and tuning magnetic properties through supramolecular chemistry principles (129 references).
Co-reporter:Hailong Wang, Kang Wang, Jun Tao and Jianzhuang Jiang
Chemical Communications 2012 vol. 48(Issue 24) pp:2973-2975
Publication Date(Web):18 Jan 2012
DOI:10.1039/C2CC16543K
Correlation between molecular structures and slow relaxation of magnetization of three mixed (phthalocyaninato)(porphyrinato) dysprosium(III) double-deckers clearly reveals the effect of the sandwich-type molecular structure, in particular the twist angle, on the quantum tunneling (QT) at zero dc field of these complexes, providing the first direct evidence to the theoretical inference.
Co-reporter:Jia Li, Jun Tao, Rong-Bin Huang, and Lan-Sun Zheng
Inorganic Chemistry 2012 Volume 51(Issue 11) pp:5988-5990
Publication Date(Web):May 24, 2012
DOI:10.1021/ic300487a
Two 3D coordination polymers, [Co24(OH)12(SO4)12(ip)6(DMSO)18(H2O)6]·(DMSO)6(EtOH)6(H2O)36 (1·guests, ip = isophthalate) and [Ni24(OH)12(SO4)12(ip)6(DMSO)12(H2O)12]·(DMSO)6(EtOH)6(H2O)20 (2·guests), constructed with nanosized tetraicosanuclear CoII and NiII wheels are solvothermally synthesized. Both complexes show intra- and interwheel dominant antiferromagnetic interactions.
Co-reporter:Rong-Jia Wei, Jun Tao, Rong-Bin Huang, and Lan-Sun Zheng
Inorganic Chemistry 2011 Volume 50(Issue 17) pp:8553-8564
Publication Date(Web):July 27, 2011
DOI:10.1021/ic201142t
Spin-crossover (SCO) complex [Fe(tpa)(NCS)2] (tpa = tri(2-pyridylmethyl)amine) crystallized in two solvate forms, yellow [Fe(tpa)(NCS)2]·X [Fe:X = 1:1; X = n-PrOH (complex is named as n-PrOH), i-PrOH (i-PrOH), CH2Cl2 (CH2Cl2), CHCl3 (CHCl3), MeCN (MeCN)] and red [Fe(tpa)(NCS)2]2·Y [Fe:Y = 2:1; Y = MeOH (MeOH), EtOH (EtOH)], respectively. Between the two forms, interesting solvent-vapor induced in situ reversible and irreversible guest molecule exchanges, [Fe(tpa)(NCS)2]·X ⇌ [Fe(tpa)(NCS)2]2·Y, occurred in the solid state followed by dramatic color changes as well as distinct structural and SCO behavior transformations. Comprehensive studies on structures and SCO behaviors associating guest exchanges have been conducted by X-ray single-crystal diffraction, PXRD, IR, elemental analysis, and magnetic measurements, respectively. This discrete molecular system shows unique solvent-dependent SCO behavior related to the nature of solvent molecules; the distinct color changes during guest exchange originate from the alternations of electronic states of the guest-sensitive FeII centers, providing an effective route to fine-tune and optimize materials’ properties by systematic structural perturbation, or serving for detection of toxic gases, such as CH2Cl2 and CHCl3.
Co-reporter:Bao Li ; Li-Qin Chen ; Rong-Jia Wei ; Jun Tao ; Rong-Bin Huang ; Lan-Sun Zheng ;Zhiping Zheng
Inorganic Chemistry 2011 Volume 50(Issue 2) pp:424-426
Publication Date(Web):December 13, 2010
DOI:10.1021/ic102270h
Herein reported is the first two-dimensional coordination polymer capable of undergoing thermally induced and photoinduced valence tautomeric transitions.
Co-reporter:Rong-Jia Wei ; Bao Li ; Jun Tao ; Rong-Bin Huang ; Lan-Sun Zheng ;Zhiping Zheng
Inorganic Chemistry 2011 Volume 50(Issue 4) pp:1170-1172
Publication Date(Web):December 7, 2010
DOI:10.1021/ic102231j
The complex [Fe(tpa)(NCS)2] showed successive polymorphic transformations (polymorphs II−IV) that produced crystals with distinct changes in color, crystal structure, and spin-crossover behavior.
Co-reporter:Feng-Lei Yang ; Jun Tao ; Rong-Bin Huang ;Lan-Sun Zheng
Inorganic Chemistry 2011 Volume 50(Issue 3) pp:911-917
Publication Date(Web):December 27, 2010
DOI:10.1021/ic101490a
The reaction of N1,N2-bis(pyridin-4-ylmethylene)ethane-1,2-diamine (L) with Fe(NCS)2 under various temperatures gave rise to three iron(II) coordination polymers, namely, one-dimensional [Fe(L′)(NCS)2] (1), two-dimensional [Fe(L)2(NCS)2]·H2O (2), and one-dimensional [Fe(L)2(NCS)2]·2CH2Cl2·4MeOH (3). The formation of 1 involved an in situ C═C coupling reaction, L to L′ [L′ = 5,6-di(pyridin-4-yl)-1,2,3,4-tetrahydropyrazine], which was catalyzed by cyanide ions decomposed from thiocyanates; the manganese(II) (1a) and zinc(II) (1b) analogues of 1 were also synthesized for comparison. Magnetic studies showed that complex 1 underwent a pressure-dependent one-step incomplete spin transition whereas complexes 2 and 3 were paramagnetic in the whole temperature range.
Co-reporter:Jia-Ping Tong ; Feng Shao ; Jun Tao ; Rong-Bin Huang ;Lan-Sun Zheng
Inorganic Chemistry 2011 Volume 50(Issue 6) pp:2067-2069
Publication Date(Web):February 22, 2011
DOI:10.1021/ic102411u
The microwave-assisted reaction of Fe(ClO4)2 with NaN3, NaO2CPh, and 1,3-di(2-pyridyl)-1,3-propanedione gave a ferrimagnetic dodecanuclear iron(III) complex that shows magnetization relaxation behavior.
Co-reporter:Rong-Jia Wei;Qian Huo; Jun Tao; Rong-Bin Huang ; Lan-Sun Zheng
Angewandte Chemie International Edition 2011 Volume 50( Issue 38) pp:8940-8943
Publication Date(Web):
DOI:10.1002/anie.201103648
Co-reporter:Rong-Jia Wei;Qian Huo; Jun Tao; Rong-Bin Huang ; Lan-Sun Zheng
Angewandte Chemie 2011 Volume 123( Issue 38) pp:9102-9105
Publication Date(Web):
DOI:10.1002/ange.201103648
Co-reporter:Jia-Ping Tong ; Xiao-Jun Sun ; Jun Tao ; Rong-Bin Huang ;Lan-Sun Zheng
Inorganic Chemistry 2010 Volume 49(Issue 4) pp:1289-1291
Publication Date(Web):January 15, 2010
DOI:10.1021/ic902205x
The reaction of CuCl2 with H2Meppz and a base under low temperature gave rise to a heptanuclear copper compound, in which a novel ligand 2,2′-bis(H2Meppz) (H4L′) was obtained through in situ C−C coupling.
Co-reporter:Bao Li ; Rong-Jia Wei ; Jun Tao ; Rong-Bin Huang ;Lan-Sun Zheng
Inorganic Chemistry 2010 Volume 49(Issue 2) pp:745-751
Publication Date(Web):December 21, 2009
DOI:10.1021/ic902161v
Spin-crossover (SCO) compounds are a sort of bistable material whose electronic and magnetic properties can be tuned by external physical stimuli, such as heat, light, and pressure. The title SCO compound [Fe(pmea)(NCS)2] (1; pmea = bis[(2-pyridyl)methyl]-2-(2-pyridyl)ethylamine) undergoes spin transition in such a way that it is an ideal candidate to investigate pressure effects on the SCO behavior. First, the spin transition is complete and abrupt so that the pressure-dependent spin transition should be remarkable. Second, the T1/2 value under ambient pressure is 184 K, which guarantees that the SCO temperature under various pressures does not exceed that restrained by high-pressure devices. The magnetic data of compound 1 under different external pressures were analyzed through a known method, as reported by Gütlich, which gave an interaction parameter Γ of 264(5) cm−1 and a volume change ΔV°HL of 32(3) Å3 molecule−1 [HL represents a high-spin (HS) ↔ low-spin (LS) transition], respectively. Meanwhile, the calculated entropy change ΔS°HL(T) at 1 bar is 59.79 J mol−1 K−1, which is a typical value that drives the spin transition from a LS to HS state. The pressure effects on the SCO behavior of compound 1 reported here may provide information for a deep understanding of the correlation between pressure and spin transition.
Co-reporter:Feng-Lei Yang, Bao Li, Taro Hanajima, Yasuaki Einaga, Rong-Bin Huang, Lan-Sun Zheng and Jun Tao
Dalton Transactions 2010 vol. 39(Issue 9) pp:2288-2292
Publication Date(Web):14 Jan 2010
DOI:10.1039/B917518K
A one-dimensional iron(II) spin-crossover compound [Fe(3py-im)2(NCS)2]·7H2O (1) (3py-im = 2,4,5-tris(4-pyridly)-imidazole) has been solvothermally synthesized and structurally characterized. Compound 1 crystallizes in the monoclinic space group P2/c with a = 11.9078(2), b = 9.9474(1), c = 17.7290(3) and β = 102.361(2)° at 105 K. Studies on the variable-temperature magnetic susceptibilities and Mössbauer spectra suggest that compound 1 undergoes incomplete spin transition behaviour. Pressure effects on the transition behaviour have also been investigated, the thermal-induced spin transition becomes more gradual and the critical temperature shifts towards slightly higher temperature range when external pressure increases. However, the spin transition can not be completed by applying external pressure even as high as 0.79 GPa.
Co-reporter:Zhong-Quan Jia, Xiao-Jun Sun, Li-Li Hu, Jun Tao, Rong-Bin Huang and Lan-Sun Zheng
Dalton Transactions 2009 (Issue 32) pp:6364-6367
Publication Date(Web):24 Jun 2009
DOI:10.1039/B903733K
A novel cobalt compound [Co9(HL)4(L)4Cl2]·(EtOH)2(H2O)2 (H3L = (E)-2-2((1,3-dihydroxy-2-methylpropan-2-ylimino)methyl) phenol) has been solvothermally synthesized and structurally characterized. The compound crystallised in the space groupC2/c with a = 32.624(2) Å, b = 9.4814(4) Å, c = 33.395(2) Å, β = 109.339(5)° and V = 9746.8(9) Å3. The crystal structure is a mixed-valence nonanuclear Co(II/III) oligomer, which contains a square-pyramidal CoII5 core formed through μ4-Cl and μ3-alkoxo bridges and the pentanuclear CoII5 core is surrounded by four peripheral Co(III) ions at the square-pyramidal base plane through μ2-alkoxo bridges. Magnetic properties of the compound can be considered as the magnetism of the CoII5 core, and the superexchange interactions between Co(II) ions within the core were calculated with three Co(II)–Co(II) superexchange parameters by using MAGPACK software package to give J1 = + 11.1 cm−1, J2 = −6.50 cm−1, J3 = −3.25 cm−1, D = + 6.0 cm−1 and g = 2.30.
Co-reporter:Xun Lin, Jun Tao, Rong-Bin Huang, Lan-Sun Zheng
Inorganic Chemistry Communications 2009 Volume 12(Issue 2) pp:154-156
Publication Date(Web):February 2009
DOI:10.1016/j.inoche.2008.12.004
A linear trinuclear Co(II) compound, [Co3(μ1,1-N3)4(N3)2(H2O)2(bpbp)2] · 2H2O (1, bpbp = 3,3′-bis-Dimethylamino-1,1′-pyridine-2,6-diyl-bispropenone), is reported. The central Co(II) ion is bridged to Co(II) ions on both sides by four end-on azide (μ1,1-N3-) ligands resulting in a centrosymmetric trimer with adjacent Co⋯Co distance of 3.233 Å. Each Co(II) ion possesses distorted octahedral geometry, the central one is coordinated by two aqua ligands and four μ1,1-N3- nitrogen atoms and each terminal Co(II) is coordinated by two μ1,1-N3- nitrogen atoms, one terminal N3- nitrogen atom and capped by terminal tridentate bpbp ligand. Variable temperature magnetic studies indicate ferromagnetic coupling between adjacent Co(II) ions within the trimer.A new linear trinuclear Co(II) compound containing end-on azide bridging ligands was structurally characterized, variable temperature magnetic susceptibility studies indicated ferromagnetic interactions between adjacent Co(II) atoms.
Co-reporter:Guo-Min Wang, Rong-Jia Wei, Li-Li Hu, Xiao-Jun Sun, Rong-Bin Huang, Lan-Sun Zheng, Jun Tao
Inorganic Chemistry Communications 2009 Volume 12(Issue 7) pp:622-624
Publication Date(Web):July 2009
DOI:10.1016/j.inoche.2009.05.005
A hexanuclear Fe(III) compound with new core topology, [Fe6(OMe)2(DHMP)4(AD)2] (1, H3DHMP = (E)-2-((1,3-dihydroxy-2-methylpropan-2-ylimino)methyl)phenol, H2AD = adipic acid), is reported. The hexanuclear Fe(III) core can be viewed as two Fe3(DHMP)2 units connected through double μ2-OMe− bridges, featuring adjacent Fe···Fe distances of 3.105 and 3.109 Å within unit and 3.111 Å between units, respectively. Variable temperature magnetic studies indicate antiferromagnetic exchanges between adjacent Fe(III) ions and which mediated by μ2-OMe− bridges is stronger than those by DHMP alkoxo bridges. Magnetic-structural correlation is also proposed.A hexanuclear Fe(III) compound with new core topology was structurally characterized, variable temperature magnetic susceptibility studies indicated antiferromagnetic interactions between adjacent Fe(III) ions.
Co-reporter:Yue-Ling Bai;Vassilis Tangoulis ;Rong-Bin Huang ;Lan-Sun Zheng Dr. Dr.
Chemistry - A European Journal 2009 Volume 15( Issue 10) pp:2377-2383
Publication Date(Web):
DOI:10.1002/chem.200802184
Co-reporter:Yue-Ling Bai, Jun Tao, Rong-Bin Huang, Lan-Sun Zheng, Shao-Liang Zheng, Kazuyoshi Oshida and Yasuaki Einaga
Chemical Communications 2008 (Issue 15) pp:1753-1755
Publication Date(Web):11 Feb 2008
DOI:10.1039/B718456E
A three-dimensional mixed-valence iron complex with NiAs-type topology, [(FeIII3O)FeII(TA)6(H2O)3]·(ClO4)2(NO3)(EtOH)(H2O)2 (1, HTA = tetrazole-1H-acetic acid), shows spin-crossover behavior that was characterized via variable-temperature crystal structures, Mössbauer spectra and magnetic susceptibilities, the pressure effects on the transition behavior were also studied.
Co-reporter:Bao Li, Feng-Lei Yang, Jun Tao, Osamu Sato, Rong-Bin Huang and Lan-Sun Zheng
Chemical Communications 2008 (Issue 45) pp:6019-6021
Publication Date(Web):14 Oct 2008
DOI:10.1039/B814944E
The effects of pressure on valence trautomeric transition behavior of two complexes, [{Co(tpa)}2(dhbq)]·(PF6)3 (I·(PF6)3) and [{Co(dpqa)}2(dhbq)]·(PF6)3 (II·(PF6)3) (tpa = tris(2-pyridylmethyl)amine, dpqa = di(2-pyridylmethyl)-N-(quinolin-2-ylmethyl)amine and dhbq = deprotonated 2,5-dihydroxy-1,4-benzoquinone), in the light of changes of magnetic susceptibilities were investigated; the results show that external pressure makes the SC + ET transition process of the two complexes into a general SC process only.
Co-reporter:Bao Li, Jun Tao, Hao-Ling Sun, Osamu Sato, Rong-Bin Huang and Lan-Sun Zheng
Chemical Communications 2008 (Issue 19) pp:2269-2271
Publication Date(Web):13 Mar 2008
DOI:10.1039/B801171K
A cobalt complex [{Co(dpqa)}2(dhbq)](PF6)3 (1(PF6)3, dhbq = deprotonated 2,5-dihydroxy-1,4-benzoquinone, dpqa = di(2-pyridylmethyl)-N-(quinolin-2-ylmethyl)amine) was prepared and studied by X-ray diffraction, electrochemistry, ESR, thermally and photo-induced magnetic measurements; the results show that the ancillary ligand finely tuned structural factors as well as intermolecular interactions that affect the VT behavior.
Co-reporter:Li-Li Hu, Zhong-Quan Jia, Jun Tao, Rong-Bin Huang and Lan-Sun Zheng
Dalton Transactions 2008 (Issue 44) pp:6113-6116
Publication Date(Web):22 Sep 2008
DOI:10.1039/B812113C
Solvothermal reaction of Co(OAc)2·4H2O with H4L (H4L = 2-((2-hydroxybenzylidene)amino)-2-hydroxymethylpropane-1,3-diol) in MeCN gave a mixed-valence pentanuclear cobalt complex [Co5(HL)2(H2L)2(OAc)2]·2.5H2O. Crystal structural analysis revealed that two Co(III) ions were linked to a central triangular Co(II) core through HL3− and H2L2− hydroxyl groups. Magnetic measurements showed interesting magnetic properties that were assigned to spin–orbital coupling and ferromagnetic exchange interactions.
Co-reporter:Yue-Ling Bai, ;Rong-Bin Huang ;Lan-Sun Zheng
Angewandte Chemie International Edition 2008 Volume 47( Issue 29) pp:5344-5347
Publication Date(Web):
DOI:10.1002/anie.200800403
Co-reporter:Yue-Ling Bai, ;Rong-Bin Huang ;Lan-Sun Zheng
Angewandte Chemie 2008 Volume 120( Issue 29) pp:5424-5427
Publication Date(Web):
DOI:10.1002/ange.200800403
Co-reporter:Jia Li, Ying Guo, Hong-Ru Fu, Jian Zhang, Rong-Bin Huang, Lan-Sun Zheng and Jun Tao
Chemical Communications 2014 - vol. 50(Issue 65) pp:NaN9164-9164
Publication Date(Web):2014/06/27
DOI:10.1039/C4CC02396J
The reaction of nickel(II) nitrate with isonicotinic acid and 2,6-dimethyl-pyridine-3,5-dicarboxylic acid affords a novel, tetranuclear nickel(II)-based metal–organic framework that exhibits spin-canted antiferromagnetism with a canted angle of 1.65° and high adsorptive selectivity for light hydrocarbons.
Co-reporter:Yue-Ling Bai, Jun Tao, Rong-Bin Huang, Lan-Sun Zheng, Shao-Liang Zheng, Kazuyoshi Oshida and Yasuaki Einaga
Chemical Communications 2008(Issue 15) pp:NaN1755-1755
Publication Date(Web):2008/02/11
DOI:10.1039/B718456E
A three-dimensional mixed-valence iron complex with NiAs-type topology, [(FeIII3O)FeII(TA)6(H2O)3]·(ClO4)2(NO3)(EtOH)(H2O)2 (1, HTA = tetrazole-1H-acetic acid), shows spin-crossover behavior that was characterized via variable-temperature crystal structures, Mössbauer spectra and magnetic susceptibilities, the pressure effects on the transition behavior were also studied.
Co-reporter:Bao Li, Jun Tao, Hao-Ling Sun, Osamu Sato, Rong-Bin Huang and Lan-Sun Zheng
Chemical Communications 2008(Issue 19) pp:NaN2271-2271
Publication Date(Web):2008/03/13
DOI:10.1039/B801171K
A cobalt complex [{Co(dpqa)}2(dhbq)](PF6)3 (1(PF6)3, dhbq = deprotonated 2,5-dihydroxy-1,4-benzoquinone, dpqa = di(2-pyridylmethyl)-N-(quinolin-2-ylmethyl)amine) was prepared and studied by X-ray diffraction, electrochemistry, ESR, thermally and photo-induced magnetic measurements; the results show that the ancillary ligand finely tuned structural factors as well as intermolecular interactions that affect the VT behavior.
Co-reporter:Jia Li, Peng Huang, Xue-Ru Wu, Jun Tao, Rong-Bin Huang and Lan-Sun Zheng
Chemical Science (2010-Present) 2013 - vol. 4(Issue 8) pp:NaN3238-3238
Publication Date(Web):2013/05/28
DOI:10.1039/C3SC51379C
Three metal-organic frameworks (MOFs) formulated as [Co3O(BTB)2(H2O)x(DMF)y]·zDMF·nH2O (BTB = 1,3,5-benzenetribenzoate; 1a, x = y = 1, z = 7.5, n = 12; 1b, x = 2, y = 0, z = 8.5, n = 8; 1c, x = 2, y = 1, z = 7, n = 8) have been synthesized under different temperatures; they crystallize as two-fold interpenetrated analogous structures with the same structural trinuclear Co3O(CO2)6 secondary building units (SBUs), and their stabilities depend on the temperature under which they formed. Upon immersion in the filtrate of 1a (namely 1a-s, freshly filtered) or 1b (namely 1b-s, filtered and then activated in air for three days), single crystal-to-single crystal (SCSC) transformations of 1a–1c to a new MOF, formulated as [Co6O2(OH)4(BTB)8/3(H2O)4]·14DMF·4EtOH·2H2O (2), occur along with dramatic color change from blue purple to red. Crystallographic studies reveal that the new MOF is also two-fold interpenetrated but is constructed with hexanuclear Co6O2(CO2)8 SBUs. This SCSC transformation from 1a–1c to 2 can take place only in 1a-s or 1b-s but not in 1c-s and is accompanied with an increase of metal-to-ligand ratio. ESI-MS studies unveil the formation of free {Co3O} units in situ formed only in 1a-s and 1b-s, and evidence that the SCSC transformation involves a postsynthetic uptake of free metal clusters, {Co3O}. On the other hand, the SCSC transformation speed decreases from 1a to 1c, which is determined by the chelate carboxylate groups undergoing cleavage of metal-carboxylate bonds during the SCSC transformation and the shape of the 1D channels affecting the diffusion of free metal clusters. Furthermore, the resulting MOF (2) can maintain its crystallinity upon activation and adsorbs iodine up to 38 wt%. Combined with the significant SCSC transformation through postsynthetic uptake of free metal clusters and the resulting MOF capable of adsorbing iodine, the present approach not only provides a true route to construct SBUs-based MOF materials with pre-existing “real” SBUs but also represent a new type of SCSC transformation in the field of MOFs that is able to efficiently tune structures and physicochemical properties of MOFs in the solid states.
Co-reporter:Zhong-Quan Jia, Xiao-Jun Sun, Li-Li Hu, Jun Tao, Rong-Bin Huang and Lan-Sun Zheng
Dalton Transactions 2009(Issue 32) pp:NaN6367-6367
Publication Date(Web):2009/06/24
DOI:10.1039/B903733K
A novel cobalt compound [Co9(HL)4(L)4Cl2]·(EtOH)2(H2O)2 (H3L = (E)-2-2((1,3-dihydroxy-2-methylpropan-2-ylimino)methyl) phenol) has been solvothermally synthesized and structurally characterized. The compound crystallised in the space groupC2/c with a = 32.624(2) Å, b = 9.4814(4) Å, c = 33.395(2) Å, β = 109.339(5)° and V = 9746.8(9) Å3. The crystal structure is a mixed-valence nonanuclear Co(II/III) oligomer, which contains a square-pyramidal CoII5 core formed through μ4-Cl and μ3-alkoxo bridges and the pentanuclear CoII5 core is surrounded by four peripheral Co(III) ions at the square-pyramidal base plane through μ2-alkoxo bridges. Magnetic properties of the compound can be considered as the magnetism of the CoII5 core, and the superexchange interactions between Co(II) ions within the core were calculated with three Co(II)–Co(II) superexchange parameters by using MAGPACK software package to give J1 = + 11.1 cm−1, J2 = −6.50 cm−1, J3 = −3.25 cm−1, D = + 6.0 cm−1 and g = 2.30.
Co-reporter:Li-Li Hu, Zhong-Quan Jia, Jun Tao, Rong-Bin Huang and Lan-Sun Zheng
Dalton Transactions 2008(Issue 44) pp:NaN6116-6116
Publication Date(Web):2008/09/22
DOI:10.1039/B812113C
Solvothermal reaction of Co(OAc)2·4H2O with H4L (H4L = 2-((2-hydroxybenzylidene)amino)-2-hydroxymethylpropane-1,3-diol) in MeCN gave a mixed-valence pentanuclear cobalt complex [Co5(HL)2(H2L)2(OAc)2]·2.5H2O. Crystal structural analysis revealed that two Co(III) ions were linked to a central triangular Co(II) core through HL3− and H2L2− hydroxyl groups. Magnetic measurements showed interesting magnetic properties that were assigned to spin–orbital coupling and ferromagnetic exchange interactions.
Co-reporter:Feng-Lei Yang, Bao Li, Taro Hanajima, Yasuaki Einaga, Rong-Bin Huang, Lan-Sun Zheng and Jun Tao
Dalton Transactions 2010 - vol. 39(Issue 9) pp:NaN2292-2292
Publication Date(Web):2010/01/14
DOI:10.1039/B917518K
A one-dimensional iron(II) spin-crossover compound [Fe(3py-im)2(NCS)2]·7H2O (1) (3py-im = 2,4,5-tris(4-pyridly)-imidazole) has been solvothermally synthesized and structurally characterized. Compound 1 crystallizes in the monoclinic space group P2/c with a = 11.9078(2), b = 9.9474(1), c = 17.7290(3) and β = 102.361(2)° at 105 K. Studies on the variable-temperature magnetic susceptibilities and Mössbauer spectra suggest that compound 1 undergoes incomplete spin transition behaviour. Pressure effects on the transition behaviour have also been investigated, the thermal-induced spin transition becomes more gradual and the critical temperature shifts towards slightly higher temperature range when external pressure increases. However, the spin transition can not be completed by applying external pressure even as high as 0.79 GPa.
Co-reporter:Yue-Ling Bai, Xiaoli Bao, Shourong Zhu, Jianhui Fang and Jun Tao
Dalton Transactions 2013 - vol. 42(Issue 4) pp:NaN1038-1038
Publication Date(Web):2012/10/16
DOI:10.1039/C2DT31944F
Two chain compounds built with anti–anti acetate bridged MnIII3O units, [Mn3O(Clppz)3(EtOH)4(OAc)]n (1) and [Mn3O(Clppz)3(EtOH)2(OAc)]n (2), were synthesized and characterized. The magnetic studies indicate that 1 is a single-chain magnet with two slow magnetization relaxation processes which has for the first time been found in this type of chain complex, while 2 shows a field-induced metamagnetic behavior. The quite different magnetic behaviors resulted from the different number of coordinated ethanol molecules on the MnIII3O unit, four ethanol molecules for 1, and two ethanol molecules for 2. The best fittings to the experimental magnetic susceptibilities gave J1 = −2.72 cm−1, J2 = −4.34 cm−1, zJ = 1.24 cm−1 for 1 and J1 = −5.91 cm−1, J2 = −0.98 cm−1, zJ = 1.71 for 2 above 30 K. The positive zJ values indicate the presence of weak ferromagnetic interactions between the trinuclear units via acetate bridges in 1 and 2.
Co-reporter:Jun Tao, Rong-Jia Wei, Rong-Bin Huang and Lan-Sun Zheng
Chemical Society Reviews 2012 - vol. 41(Issue 2) pp:NaN737-737
Publication Date(Web):2011/09/02
DOI:10.1039/C1CS15136C
The occurrence of spin-crossover (SCO) highly depends on external influences, i.e. temperature, pressure, light irradiation or magnetic field, this electronic switching phenomenon is accompanied by drastic changes in magnetic and optical properties, dielectric constants, colour and structures. Thus, SCO materials are particularly attractive for potential applications in molecular sensing, switching, data storage, display, and other electronic devices at nanometric scale. Polymorphism is widely encountered in the studies of crystallization, phase transition, materials synthesis, biomineralization, and in the manufacture of drugs. Because different crystal forms of the same substance can possess very different properties and behave as different materials, so they are particularly meaningful for investigating SCO phenomena. Studying polymorphism of SCO compounds is therefore important for better understanding the structural factors contributing to spin transition and the structure–function relationship. This critical review is aimed to provide general readers with a comprehensive view of polymorphism in SCO systems. The article is generally structured according to specific metal ions and the dimensionality of compounds in the field. This paper is addressed to readers who are interested in multifunctional materials and tuning magnetic properties through supramolecular chemistry principles (129 references).
Co-reporter:Bao Li, Feng-Lei Yang, Jun Tao, Osamu Sato, Rong-Bin Huang and Lan-Sun Zheng
Chemical Communications 2008(Issue 45) pp:NaN6021-6021
Publication Date(Web):2008/10/14
DOI:10.1039/B814944E
The effects of pressure on valence trautomeric transition behavior of two complexes, [{Co(tpa)}2(dhbq)]·(PF6)3 (I·(PF6)3) and [{Co(dpqa)}2(dhbq)]·(PF6)3 (II·(PF6)3) (tpa = tris(2-pyridylmethyl)amine, dpqa = di(2-pyridylmethyl)-N-(quinolin-2-ylmethyl)amine and dhbq = deprotonated 2,5-dihydroxy-1,4-benzoquinone), in the light of changes of magnetic susceptibilities were investigated; the results show that external pressure makes the SC + ET transition process of the two complexes into a general SC process only.
Co-reporter:Hailong Wang, Kang Wang, Jun Tao and Jianzhuang Jiang
Chemical Communications 2012 - vol. 48(Issue 24) pp:NaN2975-2975
Publication Date(Web):2012/01/18
DOI:10.1039/C2CC16543K
Correlation between molecular structures and slow relaxation of magnetization of three mixed (phthalocyaninato)(porphyrinato) dysprosium(III) double-deckers clearly reveals the effect of the sandwich-type molecular structure, in particular the twist angle, on the quantum tunneling (QT) at zero dc field of these complexes, providing the first direct evidence to the theoretical inference.
Co-reporter:Xiang-Yi Chen, Hai-Yan Shi, Rong-Bin Huang, Lan-Sun Zheng and Jun Tao
Chemical Communications 2013 - vol. 49(Issue 93) pp:NaN10979-10979
Publication Date(Web):2013/10/07
DOI:10.1039/C3CC45691A
A 3D 2-fold interpenetrated porous coordination polymer, [Fe(NCS)2(tppm)]·5CH3OH·2CH2Cl2 (1·sol, tppm = 4,4′,4′′,4′′′-tetrakis(4-pyridylethen-2-yl)tetraphenylmethane), was synthesized, which showed temperature, light and solvent-induced spin-crossover behaviours.
Co-reporter:Feng Shao, Jia Li, Jia-Ping Tong, Jian Zhang, Ming-Guang Chen, Zhiping Zheng, Rong-Bin Huang, Lan-Sun Zheng and Jun Tao
Chemical Communications 2013 - vol. 49(Issue 91) pp:NaN10732-10732
Publication Date(Web):2013/09/27
DOI:10.1039/C3CC45180A
A metal–organic framework, [{Fe(NCS)2}3(TPB)4]·x(guest) [1·x(guest), TPB = 1,3,5-tris(4-pyridyl)benzene], shows selective gas adsorption and guest-dependent spin-crossover behaviour.
![2-Pyridineethanamine, N-[2-(2-pyridinyl)ethyl]-N-(2-pyridinylmethyl)-](http://img.cochemist.com/ccimg/236800/236745-06-5.png)
![2-Pyridineethanamine, N-[2-(2-pyridinyl)ethyl]-N-(2-pyridinylmethyl)-](http://img.cochemist.com/ccimg/236800/236745-06-5_b.png)
![Pyridine, 4,4'-[[2,2-bis[(4-pyridinyloxy)methyl]-1,3-propanediyl]bis(oxy)]bis-](/data/chemimg/102500/163629-49-0.png)
![Pyridine, 4,4'-[[2,2-bis[(4-pyridinyloxy)methyl]-1,3-propanediyl]bis(oxy)]bis-](/data/chemimg/102500/163629-49-0_b.png)
![[1,1'-Biphenyl]-3,5-dicarboxylicacid](/data/chemimg/44500/4445-59-4.png)
![[1,1'-Biphenyl]-3,5-dicarboxylicacid](/data/chemimg/44500/4445-59-4_b.png)
