Co-reporter:Yuqi Jia, Liping Lu, Miaoli Zhu, Caixia Yuan, Shu Xing, Xueqi Fu
European Journal of Medicinal Chemistry 2017 Volume 128(Volume 128) pp:
Publication Date(Web):10 March 2017
DOI:10.1016/j.ejmech.2017.02.003
•A new dioxidovanadium (V) complex (1) was synthesized and characterized.•Complex 1 potently and selectively inhibited protein tyrosine phosphatase 1B (PTP1B).•Complex 1 effectively increased the phosphorylation of PTP1B substrates.•Complex 1 exhibited lower cytotoxicity than the positive control VOSO4.A new dioxidovanadium (V) complex, VO2(HPPCH) (1) (H2PPCH = N'-picolinoylpyridin-1-ium-2-carbohydrazonate) has been synthesized and characterized by elemental analysis, IR, X-ray diffraction analysis and electrospray ionization mass spectra. Complex 1 crystallized in the monoclinic system with space group P21/c. It potently inhibited PTP1B with IC50 of 0.13 μM, about 7, 15 and 125-fold stronger against PTP1B than over TCPTP, SHP-1 and SHP-2, displaying obvious selectivity against PTP1B. Western blotting analysis indicated that complex 1 effectively increased the phosphorylation of PTP1B substrates, especially the phosphorylation of IR/IGF 1R and IRS-1. It exhibited lower cytotoxicity than positive control VOSO4. These results make complex 1 a promising candidate for novel anti-diabetic drug development.A new dioxidovanadium (V) complex (1) has been synthesized and characterized. It potently and selectively inhibited protein tyrosine phosphatase 1B, increased the phosphorylation of PTP1B substrates and exhibited lower cytotoxicity than VOSO4, suggesting a promising candidate for novel vanadium-based anti-diabetic drug.Download high-res image (240KB)Download full-size image
Co-reporter:Li-Yang Zhang;Li-Ping Lu;Miao-Li Zhu;Si-Si Feng
CrystEngComm (1999-Present) 2017 vol. 19(Issue 14) pp:1953-1964
Publication Date(Web):2017/04/03
DOI:10.1039/C7CE00149E
Based on a bifunctional 2-(pyridine-2-yl)-1H-4,5-imidazole-dicarboxylic acid ligand, a novel family of lanthanide coordination polymers with formulas [Ln(HPIDC)(C2O4)0.5(H2O)]n (Ln = La, 1; Ce, 2) and [Ln2(HPIDC)(C2O4)2(H2O)3]n·2nH2O (Ln = Pr, 3; Nd, 4; Sm, 5; Eu, 6; Gd, 7; Tb, 8; Dy, 9; Ho, 10; Er, 11), (H3PIDC = 2-(pyridine-2-yl)-1H-imidazole-4,5-dicarboxylic acid & H2C2O4 = oxalic acid) has been prepared under hydro-solvothermal conditions and characterized by single crystal X-ray diffraction, elemental analysis, IR spectroscopy, and thermogravimetric analysis. Notably, the ligands adopt the same μ3-kN,O:kO′,O′′:kO′′′ conformation in all compounds, which brings about two types of isostructural lanthanide coordination polymers. Namely, 1 and 2 crystallize in the monoclinic space group P21/n and are composed of [Ln2(COO)2] dinuclear subunits with networks having the symbol (63·82·10)2(63)2(8). Meanwhile, 3–11 crystallize in the monoclinic space group P21/c and are constructed with tetranuclear [Ln4(COO)4] subunits with networks having the symbol (103)2(104·122)(10)2. The photoluminescence measurement indicates that Eu(III) and Tb(III) coordination polymers show very strong reddish-orange and green emission bands with CIE chromaticity coordinates (0.612, 0.325) and (0.284, 0.523) and quantum yields of 54.3% & 34.7%, respectively. The magnetic properties of 3 and 7–11 are investigated, and the results indicate a ferromagnetic interaction between Gd(III) magnetic centers in complex 7 and antiferromagnetic interactions in other complexes.
Co-reporter:Yuqi Jia, Liping Lu, Caixia Yuan, Sisi Feng, Miaoli Zhu
Journal of Inorganic Biochemistry 2017 Volume 170(Volume 170) pp:
Publication Date(Web):1 May 2017
DOI:10.1016/j.jinorgbio.2017.02.011
•The 97 putative Cu-binding proteins from rat hepatocytes were isolated and identified.•Aspartate aminotransferase was potently inhibited by copper complexes 6 and 7.•Complex 6 entered into cells and inhibited intracellular aspartate aminotransferase.Recent researches indicated that a copper complex-binding proteome that potently interacted with copper complexes and then influenced cellular metabolism might exist in organism. In order to explore the copper complex-binding proteome, a copper chelating ion-immobilized affinity chromatography (Cu-IMAC) column and mass spectrometry were used to separate and identify putative Cu-binding proteins in primary rat hepatocytes. A total of 97 putative Cu-binding proteins were isolated and identified. Five higher abundance proteins, aspartate aminotransferase (AST), malate dehydrogenase (MDH), catalase (CAT), calreticulin (CRT) and albumin (Alb) were further purified using a SP-, and (or) Q-Sepharose Fast Flow column. The interaction between the purified proteins and selected 11 copper complexes and CuCl2 was investigated. The enzymes inhibition tests demonstrated that AST was potently inhibited by copper complexes while MDH and CAT were weakly inhibited. Schiff-based copper complexes 6 and 7 potently inhibited AST with the IC50 value of 3.6 and 7.2 μM, respectively and exhibited better selectivity over MDH and CAT. Fluorescence titration results showed the two complexes tightly bound to AST with binding constant of 3.89 × 106 and 3.73 × 106 M− 1, respectively and a stoichiometry ratio of 1:1. Copper complex 6 was able to enter into HepG2 cells and further inhibit intracellular AST activity.The 97 putative Cu-binding proteins from primary rat hepatocytes were isolated and identified. Five putative Cu-binding proteins were further purified and the interaction between them and copper complexes was investigated. Complexes 6 and 7 potently inhibited aspartate aminotransferase (AST) and 6 entered into HepG2 cells and inhibited intracellular AST activity.Download high-res image (82KB)Download full-size image
Co-reporter:Sisi Feng, Fei Jia, Liping Lu, Zhongping Li and Shuo Zhang
Chemical Communications 2016 vol. 52(Issue 23) pp:4294-4297
Publication Date(Web):19 Feb 2016
DOI:10.1039/C6CC00399K
The first 32-membered Cu(II) cluster with a big cubic structure consisting of eight small cubic cores exhibited a high photocatalytic activity for the degradation of rhodamine B (∼99%) dye within 15 min under UV light irradiation, effective electrocatalytic activity for nitrite reduction and strong antiferromagnetic interactions among the Cu(II) centers.
Co-reporter:Ya-Hui Liu, Li-Ping Lu, Miao-Li Zhu, Si-Si Feng and Feng Su
Dalton Transactions 2016 vol. 45(Issue 22) pp:9267-9278
Publication Date(Web):29 Apr 2016
DOI:10.1039/C5DT04953A
Three new Ni(II)-clusters based on a Y-shaped ligand (biphenyl-3,4′,5-tricarboxylate, H3BPT), [Ni5(HBPT)4(OH)2(H2O)12]n (1), [Ni4(BPT)2(OH)2(H2O)6]n·4nH2O (2), and [Ni7(BPT)2(1,4-bib)2(OH)6(HCO2)2]n·3nH2O (3) (1,4-bib = 1,4-bi(1H-imidazol-1-yl)benzene), have been synthesized under solvothermal conditions. They were studied by infrared spectroscopy (IR), single crystal X-ray diffraction, thermogravimetric analysis (TGA), and magnetochemistry. The complexes contain low nuclear Ni-clusters as building units (BUs). Structurally, in 1, the cluster BUs of [Ni5(μ3-OH)2]8+ can be viewed as two reverse triangles sharing a common vertex, which are connected by the partially deprotonated μ2–η1:η1-HBPT2− forming 1D chains. The BUs of [Ni4(μ3-OH)2]6+ clusters in 2 can be considered as two reverse triangles sharing a common edge and extended by deprotonated μ6–η1:η1:η1:η1:η2-BPT3− constructing a 2D framework. The 3D framework of complex 3 consists of a [Ni7(μ3-OH)4(R-COO)7(HCO2)3] cluster BUs with fully deprotonated μ5–η1:η1:η1:η1:η1:η1-BPT3− and 1,4-bib ligands. In addition, TGA reveals that the complexes are stable in the range of 293–548 K. Magnetostructural analyses indicate ferromagnetic coupling of J1 = 1.85(3) and J2 = 2.25(4) cm−1 in 1 and J = 5.76(6) cm−1 in 2, whereas magnetic parameters J1 = −2.64(3), J2 = −23.22(19) and J3 = 12.02(5) cm−1 indicate an alternating magnetic chain (AF/F) in 3.
Co-reporter:Yu-Qi Jia, Si-Si Feng, Mei-Lin Shen and Li-Ping Lu
CrystEngComm 2016 vol. 18(Issue 28) pp:5344-5352
Publication Date(Web):23 May 2016
DOI:10.1039/C6CE00308G
In order to obtain multifunctional molecular-based materials, especially multiferroics, a polar structure is essential. In this study, we find that intelligently using the K+ cation can effectively achieve this goal in the Tb3+-croconate hybrid system. Four rationally designed complexes based on Tb3+ and croconic acid have been synthesized and structurally characterized. The complexes have the formula [Tb2(C5O5)3(H2O)12]·2H2O (1), [KTb(C5O5)2(H2O)6]·1.5H2O (2), [Tb(C5O5)(Hdpa)(H2O)5]·H2O (3) and [KTb(C5O5)2(H2O)5]·2H2O (4), (H2C5O5 = croconic acid, H2dpa = 2,5-dipicolinic acid). The structures of the complexes were remarkably different after K+ was introduced. Complex 1, constructed by eight-coordinate Tb3+ nodes connected with C5O52− and H2O, is a novel 0D metal–organic architecture with abundant O–H⋯O hydrogen bonds, whereas complex 2 is a 1D chain built by C5O52− spacers bridging five-coordinate K+ and eight-coordinate Tb3+ ions. Complex 3 has deprotonated C5O52− and Hdpa− anions connected to an eight-coordinate Tb3+ center, to give a polar 0D structure. Complex 4, constructed by nine-coordinate Tb3+ and ten-coordinate K+ nodes connected with C5O52− and H2O, is a novel, polar 3D metal–organic architecture. The fluorescence spectra of 1–4 show characteristic emission bands of Tb3+ ions. Interestingly, the fluorescence intensities of complexes 3 and 4, especially emissions at 370 nm, are significantly enhanced compared to the intensities of 1 and 2, owing to the structural differences. Magnetic susceptibility studies of complexes 1–4 show similar patterns. Furthermore, complex 4 exhibits a ferroelectric hysteresis loop at room temperature, due to its polarity. Thus, in this work, by merely adjusting the polarity of the structure, a series of different, versatile compounds were obtained as potential multifunctional materials.
Co-reporter:Feng Su, Liping Lu, Miaoli Zhu, Sisi Feng
Journal of Molecular Structure 2016 Volume 1108() pp:451-457
Publication Date(Web):15 March 2016
DOI:10.1016/j.molstruc.2015.12.037
•The compound (I) was synthesized under simple hydrothermal conditions.•The pseudo-interpenetrated framework is formed by interlocked metal-organic moiety and neutral H4bpta ligand segment.•The compound (I) exhibits an interesting interweaving framework with a new (3,4,5)-connected topological structure.A mixture of 1,1′-biphenyl-3,3′,5,5′-tetracarboxylate acid (abbreviated as H4bpta), 4,4′-bipyridine (abbreviated as 4,4′-bipy), and CuCl2·2H2O generates co-crystallization supramolecular solids [Cu2(cis-H2bpta)2(4,4′-bipy)2]n·nH4bpta·2nH2O (I) under hydrothermal condition and form of partly deprotonated cis-H2bpta2− firstly emerges in this work. Crystallographically, a 1:1 co-crystal is formed by co-crystallization of [Cu2(cis-H2bpta)2(4,4′-bipy)2] and H4bpta in self-assembled process. Structurally, the compound (I) exhibits two-dimensional (2D) double-layered nets with a pseudo-interpenetrated skeleton, one layer is characteristic of metal-organic moiety linked via cis-H2bpta2− and 4,4′-bipy spaces, and the other formed by O–H···O H-bonds presented in neutral H4bpta ligands. Interestingly, its mechanically interlocked structure is formed by hydrogen bonds, which results in an interesting interweaving framework with a new (3,4,5)-connected topological structure. Magnetic couplings between adjacent Cu(II) centers are mediated through double syn-syn carboxylate bridges. Magnetic susceptibility measurement indicates that (I) exhibits a dinuclear Cu(II) behavior with antiferromagnetic coupling (J = −35.69(1) cm−1).A 1:1 cocrystal is formed by cocrystallization of [Cu2(cis-H2bpta)2(4,4′-bipy)2] and H4bpta in self-assembled process, which exhibits 2D interweaving layered nets via hydrogen bonds based on the two types hetero-molecules.
Co-reporter:Caixia Yuan, Xinyu Liu, Yanbo Wu, Liping Lu, Miaoli Zhu
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 2016 Volume 154() pp:215-219
Publication Date(Web):5 February 2016
DOI:10.1016/j.saa.2015.10.035
•A simple but effective fluorescence sensor for Zn2 + was investigated.•The detection limit of HL for Zn2 + could reach at 10− 8M level.•The mechanism of HL for detecting Zn2 + was evaluated by TD-DFT calculations.A triazole-Schiff base, 4-(5-Chloro-2-hydroxybenzylideneamino)-1H-1,2,4-triazole-5(4H)-thione (HL), exhibits the high selectivity and sensitivity for Zn2 + in the fluorescence spectrometry over other common metal ions, especially Cd2 + in DMSO:H2O (1:9, v/v) solution. A 1:1 binding ratio of Zn2 +/L for the complex has been obtained by Uv–Vis titration experiments and Job's plot with the detection limit of 51 nmol/L. The coordination mode of the complex in solution was further confirmed by density functional theory (DFT) calculations. Time-dependent density functional theory (TD-DFT) calculations indicate that a chelation-enhanced fluorescence (CHEF) effect occurs in the process of detecting Zn ion.A simple but high selectivity and sensitivity fluorescent sensor for Zn2 + based on triazole Schiff base was reported using the combined experimental and theoretical study methods.
Co-reporter:Ya-Hui Liu;Li-Ping Lu;Miao-Li Zhu;Feng Su
Acta Crystallographica Section C 2016 Volume 72( Issue 4) pp:358-362
Publication Date(Web):
DOI:10.1107/S2053229616004824
Coordination polymers (CPs) built by coordination bonds between metal ions/clusters and multidentate organic ligands exhibit fascinating structural topologies and potential applications as functional solid materials. The title coordination polymer, poly[diaquabis(μ4-biphenyl-3,4′,5-tricarboxylato-κ4O3:O3′:O4′:O5)tris[μ2-1,4-bis(1H-imidazol-1-yl)benzene-κ2N3:N3′]dicopper(II)dicopper(I)], [CuII2CuI2(C15H7O6)2(C12H10N4)3(H2O)2]n, was crystallized from a mixture of biphenyl-3,4′,5-tricarboxylic acid (H3bpt), 1,4-bis(1H-imidazol-1-yl)benzene (1,4-bib) and copper(II) chloride in a water–CH3CN mixture under solvothermal reaction conditions. The asymmetric unit consists of two crystallographically independent Cu atoms, one of which is CuII, while the other has been reduced to the CuI ion. The CuII centre is pentacoordinated by three O atoms from three bpt3− ligands, one N atom from a 1,4-bib ligand and one O atom from a coordinated water molecule, and the coordination geometry can be described as distorted trigonal bipyramidal. The CuI atom exhibits a T-shaped geometry (CuN2O) coordinated by one O atom from a bpt3− ligand and two N atoms from two 1,4-bib ligands. The CuII atoms are extended by bpt3− and 1,4-bib linkers to generate a two-dimensional network, while the CuI atoms are linked by 1,4-bib ligands, forming one-dimensional chains along the [20] direction. In addition, the completely deprotonated μ4-η1:η1:η1:η1 bpt3− ligands bridge one CuI and three CuII cations along the a (or [100]) direction to form a three-dimensional framework with a (103)2(10)2(42.6.102.12)2(42.6.82.10)2(8) topology via a 2,2,3,4,4-connected net. An investigation of the magnetic properties indicated a very weak ferromagnetic behaviour.
Co-reporter:Li-Yang Zhang;Li-Ping Lu;Si-Si Feng
Acta Crystallographica Section C 2016 Volume 72( Issue 8) pp:652-657
Publication Date(Web):
DOI:10.1107/S205322961601161X
Coordination polymers are a thriving class of functional solid-state materials and there have been noticeable efforts and progress toward designing periodic functional structures with desired geometrical attributes and chemical properties for targeted applications. Self-assembly of metal ions and organic ligands is one of the most efficient and widely utilized methods for the construction of CPs under hydro(solvo)thermal conditions. 2-(Pyridin-3-yl)-1H-imidazole-4,5-dicarboxylate (HPIDC2−) has been proven to be an excellent multidentate ligand due to its multiple deprotonation and coordination modes. Crystals of poly[aquabis[μ3-5-carboxy-2-(pyridin-3-yl)-1H-imidazole-4-carboxylato-κ5N1,O5:N3,O4:N2]copper(II)dicopper(I)], [CuIICuI2(C10H5N3O4)2(H2O)]n, (I), were obtained from 2-(pyridin-3-yl)-1H-imidazole-4,5-dicarboxylic acid (H3PIDC) and copper(II) chloride under hydrothermal conditions. The asymmetric unit consists of one independent CuII ion, two CuI ions, two HPIDC2− ligands and one coordinated water molecule. The CuII centre displays a square-pyramidal geometry (CuN2O3), with two N,O-chelating HPIDC2− ligands occupying the basal plane in a trans geometry and one O atom from a coordinated water molecule in the axial position. The CuI atoms adopt three-coordinated Y-shaped coordinations. In each [CuN2O] unit, deprotonated HPIDC2− acts as an N,O-chelating ligand, and a symmetry-equivalent HPIDC2− ligand acts as an N-atom donor via the pyridine group. The HPIDC2− ligands in the polymer serve as T-shaped 3-connectors and adopt a μ3-κ2N,O:κ2N′,O′:κN′′-coordination mode, linking one CuII and two CuI cations. The Cu cations are arranged in one-dimensional –Cu1–Cu2–Cu3– chains along the [001] direction. Further crosslinking of these chains by HPIDC2− ligands along the b axis in a –Cu2–HPIDC2−–Cu3–HPIDC2−–Cu1– sequence results in a two-dimensional polymer in the (100) plane. The resulting (2,3)-connected net has a (123)2(12)3 topology. Powder X-ray diffraction confirmed the phase purity for (I), and susceptibilty measurements indicated a very weak ferromagnetic behaviour. A thermogravimetric analysis shows the loss of the apical aqua ligand before decomposition of the title compound.
Co-reporter:Feng Su, Liping Lu, Sisi Feng, Miaoli Zhu, Zengqiang Gao and Yuhui Dong
Dalton Transactions 2015 vol. 44(Issue 16) pp:7213-7222
Publication Date(Web):04 Mar 2015
DOI:10.1039/C5DT00412H
To evaluate magnetic properties of isostructural compounds, a series of 3D carboxylate coordination polymers [M(H2bpta)]n, (H4bpta = 2,2′,4,4′-biphenyltetracarboxylic acid, M = Fe(II) (1), Ni(II) (2), Cu(II) (3) and Zn(II) (4)), was synthesized in H2O–CH3CN or H2O solvents, respectively. Structurally, complexes 1–4 have isostructural features with (5,5)-connected 3D framework, wherein the M(II) centre takes an octahedral coordination environment consisting of six oxygen atoms from carboxylates of ligands. The M(II) sites are linked by syn–anti carboxylates to form chains with an M⋯M separation of 4.880(2) (M = Fe), 4.784(2) (M = Ni), 4.541(2) (M = Cu), and 4.607(2) Å (M = Zn), respectively. The shortest M⋯M distances between interchains locate 9.122(4), 9.077(3), 9.361(3), and 8.767(2) Å, respectively. Magnetically, the isostructural polymers show different magnetic behaviors due to different spins of central ions. Theoretical analysis indicates that couplings between magnetic ions obey uniform chain models. The magnetic susceptibility of 1 and 2 are perfectly fitted by the modified Fisher model to yield an effective intra-chain exchange coupling constant of −0.81(1) and 3.67(2) cm−1, respectively. For 3, a Heisenberg ferromagnetic S = 1/2 chain included the intra-chain magnetic exchange interaction (J = 9.28(1) cm−1, and zj′ = −0.068(3) cm−1), weak ferromagnetic interactions in intra-chains, and weak antiferromagnetic interactions between interchains. The phenomena of 1–3 accord with the common view that the exchange interaction between two magnetic M(II) ions bridged by the syn–anti carboxylate bridge is dominantly weak ferro- or anti-ferromagnetic interactions. In addition, the M–O–C–O–M spin exchange interactions |J| of M2(CO2)2 (M = Mn(3d5)20, Fe(3d6), Co(3d7)20, Ni(3d8), Cu(3d9)) decrease in strength with Cu2(CO2)2 > Ni2(CO2)2 > Co2(CO2)2 > Fe2(CO2)2 > Mn2(CO2)2, consistent with orbit order.
Co-reporter:Feng Su ;Li-Ping Lu
Acta Crystallographica Section C 2015 Volume 71( Issue 7) pp:534-538
Publication Date(Web):
DOI:10.1107/S2053229615010992
The title coordination polymer, poly[[aqua(μ5-1,1′-biphenyl-2,2′,5,5′-tetracarboxylato)bis[μ2-1,4-bis(1H-imidazol-1-yl)benzene]dicadmium(II)] dihydrate], {[Cd2(C16H6O8)(C12H10N4)2(H2O)]·2H2O}n, was crystallized from a mixture of 1,1′-biphenyl-2,2′,5,5′-tetracarboxylic acid (H4bpta), 1,4-bis(1H-imidazol-1-yl)benzene (1,4-bib) and cadmium nitrate in water–dimethylformamide. The crystal structure consists of two crystallographically independent CdII cations, with one of the CdII cations possessing a slightly distorted pentagonal bipyramidal geometry. The second CdII centre is coordinated by carboxylate O atoms and imidazole N atoms from two separate 1,4-bib ligands, displaying a distorted octahedral CdN2O4 geometry. The completely deprotonated bpta4− ligand, exhibiting a new coordination mode, bridges five CdII cations to form one-dimensional chains viaμ3-η1:η2:η1:η2 and μ2-η1:η1:η0:η0 modes, and these are further linked by 1,4-bib ligands to form a three-dimensional framework with a (42.64)(4.62)(43.65.72) topology. The structure of the coordination polymer is reinforced by intermolecular hydrogen bonding between carboxylate O atoms, aqua ligands and crystallization water molecules. The solid-state photoluminescence properties were investigated and the complex might be a candidate for a thermally stable and solvent-resistant blue fluorescent material.
Co-reporter:Feng Su, Liping Lu, Sisi Feng and Miaoli Zhu
CrystEngComm 2014 vol. 16(Issue 34) pp:7990-7999
Publication Date(Web):04 Jul 2014
DOI:10.1039/C4CE01020E
Solvothermal or hydrothermal methods of M(NO3)2·6H2O (M = Ni(II) or Co(II)) with an N donor (1,4-bis(imidazol-1-yl)benzene, 1,4-bib) and auxiliary deprotonated biphenyltetracarboxylates (2,2′,5,5′-biphenyltetracarboxylic acid, H4(o,m-bpta); 3,3′,5,5′-biphenyltetracarboxylic acid, H4(m,m-bpta); or 3,3′,4,4′-biphenyltetracarboxylic acid, H4(m,p-bpta)) give five novel coordination polymers in H2O–DMF or H2O, namely, [Ni2(1,4-bib)3(o,m-bpta)(H2O)2] (1), [Ni2(1,4-bib)3(HCO2)4(H2O)2]·5H2O (2), [Co2(1,4-bib)2(m,m-bpta)(H2O)4] (3), [Ni2(1,4-bib)2(m,p-bpta)(H2O)2] (4) and [Co2(1,4-bib)2(m,p-bpta)(H2O)2] (5). The structural properties of the complexes have been acquired by single-crystal XRD and further characterized by EA, IR spectroscopy, powder XRD and TG analysis. The framework of 1 is constructed of a 3D interpenetration structure with a (4·62)2(42·62·82) topology. Complex 2 exhibits a 3D supramolecular framework assembled by 1D mutual interpenetration chains. Complex 3 generates a 3D supramolecular architecture from (4,4)-connected 2D layers. Complexes 4 and 5 exhibit isomorphism, having 2D sheet structures with (4,4)-grid units. These results reveal that the 1,4-bib ligand cooperating with different biphenyltetracarboxylic acids can be used as versatile building blocks for the construction of metal–organic frameworks. Magnetic susceptibility measurements indicate the presence of weak ferromagnetic exchanges between adjacent Ni(II) ions with g = 2.235(5), 2.223(7) and J = 0.906(1), 2.220(1) cm−1 for 1 and 4, respectively.
Co-reporter:Ruiting Zhu, Liping Lu, Miaoli Zhu, Hong Han, Caixia Yuan, Shu Xing, Xueqi Fu
Inorganica Chimica Acta 2013 Volume 405() pp:91-97
Publication Date(Web):24 August 2013
DOI:10.1016/j.ica.2013.05.018
•Schiff-base copper complexes were synthesized and characterized.•The complexes noncompetitively inhibit PTP1B, TCPTP, PTP-MEG2 & SHP-1 but SHP-2.•Complex 5 exhibits very strong inhibition and better selectivity against PTP1B.Five copper complexes, [Cu(bhbb,chbb,nhbb)(H2O)n] (tridentate-ligands: H2bhbb = 2-(5-bromo-2-hydroxylbenzylideneamino)benzoic acid, 1; H2chbb = 2-(5-chloro-2-hydroxylbenzylideneamino)benzoic acid, 2; H2nhbb = 2-(5-nitro-2-hydroxyl-benzylideneamino)benzoic acid, 3) and [Cu(cpmp,npmp)2] (bidentate-ligands: Hcpmp = 4-chloro-2-((phenylimino)methyl)phenol, 4; Hnpmp = 4-bromo-2-((phenyl-imino)methyl)phenol, 5) have been prepared and characterized by EA, IR, EPR UV–Vis, and ESI-MS. Structure–activity relationship of copper complexes in inhibiting protein tyrosine phosphatases (protein tyrosine phosphatase 1B, PTP1B; T-cell protein tyrosine phosphatase, TCPTP; megakaryocyte protein-tyrosine phosphatase, PTP-MEG2; Src homology phosphatase 1, SHP-1 and Src homology phosphatase 2, SHP-2) is investigated. Inhibitory activities of complexes against the five PTPs indicate that they potently inhibit PTP1B, TCPTP, PTP-MEG2 and SHP-1, but do not inhibit SHP-2. In the complexes, 5 exhibits very strong inhibition (IC50, 0.059 μM) and better selectivity against PTP1B while 1 and 2 show very strong inhibition (IC50 = 0.089 and 0.067 μM) and a little selectivity against TCPTP. Compared with the oxovanadium(IV) complexes of same ligands, the copper complexes increase the inhibitory ability against TCPTP, PTP-MEG2 and SHP-1 but decrease the inhibition against SHP-2. For complex 5, the inhibition over PTP1B, TCPTP, PTP-MEG2 and SHP-1 are all improved about 5- to 15-fold compared with the oxovanadium(IV) complex. The results demonstrate that both the ligand structures and the center metals influence the inhibition and selectivity against different PTPs.Five copper complexes of Schiff-base condensates from 5-substituted-2-hydroxy-benzaldehyde and 2-substituted-benzenamine were synthesized and characterized. The copper complexes noncompetitively inhibit PTP1B, TCPTP, PTP-MEG2 and SHP-1, but do not inhibit SHP-2. Complex 5 exhibits very strong inhibition and better selectivity against PTP1B (IC50 = 0.059 μM).
Co-reporter:Caixia Yuan, Miaoli Zhu, Qingming Wang, Liping Lu, Shu Xing, Xueqi Fu, Zheng Jiang, Shuo Zhang, Zongwei Li, Zhuoyu Li, Ruiting Zhu, Ling Ma and Liqing Xu
Chemical Communications 2012 vol. 48(Issue 8) pp:1153-1155
Publication Date(Web):25 Nov 2011
DOI:10.1039/C2CC16818A
A dinuclear Cu(II) complex, [Cu2(μ-IDA)(phen)3(NO3)]NO3·4H2O (phen = 1,10-phenanthroline, H2IDA = iminodiacetic acid), was found to potently and selectively inhibit T-cell protein tyrosine phosphatase, and lead to the anti-proliferation and apoptosis of C6 glioma cells.
Co-reporter:Qingming Wang, Miaoli Zhu, Ruiting Zhu, Liping Lu, Caixia Yuan, Shu Xing, Xueqi Fu, Yuhua Mei, Qingwei Hang
European Journal of Medicinal Chemistry 2012 Volume 49() pp:354-364
Publication Date(Web):March 2012
DOI:10.1016/j.ejmech.2012.01.038
Seventeen α-aminophosphonates are synthesized. Their compositions and structures are established by EA, UV, FT-IR, 1H NMR, 13C NMR, 31P NMR and ESI-MS. Compounds 1–4 are confirmed by X-ray crystallography. PTP inhibition shows compounds 1–5, 12, 15 are moderate competitive inhibitors with some selectivity. The most potent inhibitor is compound 5 with the lowest IC50 value about 6.64 μM against PTP1B, about 2-fold and 25-fold stronger than against TCPTP and PTP-MEG2 while it doesn't inhibit SHP-1 and SHP-2. The binding constant of 5 to PTP1B is 2.23 × 105 M−1 and binding ratio approximates 1:1. Cell viability and apoptosis assays indicate 5 is cell permeable with lower cytotoxicity. The results indicate α-aminophosphonates are possibly developed to effective and selective inhibitors of PTPs.Highlights► New α-aminophosphonates are synthesized and characterized. ► PTP inhibition assays show 5 potently and selectively inhibits PTP1B and TCPTP. ► Compound 5 is cell permeable with lower cytotoxicity.
Co-reporter:Sisi Feng, Haigang Lv, Zhongping Li, Guoqin Feng, Liping Lu and Miaoli Zhu
CrystEngComm 2012 vol. 14(Issue 1) pp:98-102
Publication Date(Web):15 Nov 2011
DOI:10.1039/C1CE06215H
Hydrothermal reaction of CuBr2 and 1,2-di(1H-benzoimidazol-2-yl)ethane-1,2-diol leads to the formation of a new mixed-valence copper(I,II) complex [(C7H5N2)(CuICuIIBr2)], which exhibits a two-dimensional layer structure, containing the first example of a rhombic dodecahedral CuBr [4,3] polyhedral column. The synthesis, crystal structure, electronic property, thermal stability and electrochemical characterization of this complex are investigated.
Co-reporter:Ling Ma, Liping Lu, Miaoli Zhu, Qingming Wang, Fei Gao, Caixia Yuan, Yanbo Wu, Shu Xing, Xueqi Fu, Yuhua Mei, Xiaoli Gao
Journal of Inorganic Biochemistry 2011 Volume 105(Issue 9) pp:1138-1147
Publication Date(Web):September 2011
DOI:10.1016/j.jinorgbio.2011.05.015
Three dinuclear copper complexes of organic claw ligands (2,2′,2″,2‴-(5-R-2-hydroxy-1,3-phenylene)bis(methylene)bis(azanetriyl)tetraacetic acid, R = methyl (H5L1), chloro (H5L2) and bromo (H5L3)): [Cu2NaL1(H2O)2] (1), [Cu2HL2(H2O)2] (2), [Cu2NaL3(H2O)2] (3), have been synthesized and characterized by elemental analyses, infrared spectra, thermo-gravimetric analyses, X-ray diffraction analysis, electrospray ionization mass spectra, pH-potentiometric titration, molar conductivity. Their inhibitory effects against human protein tyrosine phosphatase 1B (PTP1B), T cell protein tyrosine phosphatase (TCPTP), Megakaryocyte protein tyrosinephosphatase 2 (PTP-MEG2), srchomology phosphatase 1 (SHP-1) and srchomology phosphatase 2 (SHP-2) are evaluated in vitro. The three copper complexes exhibit potent and almost same inhibition against PTP1B and SHP-1 with IC50 values ranging from 0.15 to 0.31 μM, about 2-fold stronger inhibition than against PTP-MEG2, 10-fold stronger inhibition than against TCPTP, but almost no inhibition against SHP-2. Kinetic analysis indicates that they are reversible competitive inhibitors of PTP1B. Molecular docking analyses confirm the inhibition model. Fluorescence titration studies suggest that the complexes bond to PTP1B with the formation of a 1:1 complex. The results demonstrate that copper complexes that are potent PTPs inhibitors but have different inhibitory effects over different PTPs, may be explored as new practical inhibitors towards individual PTP with some specificity.Three dinuclear copper complexes of organic claw ligands (2,2′,2″,2‴-(5-R-2-hydroxy-1,3-phenylene)bis(methylene)bis(azanetriyl)tetraacetic acid) have been synthesized and characterized, which exhibit potent same inhibition against PTP1B and SHP-1, about 2-fold stronger inhibition than against PTP-MEG2, 10-fold stronger inhibition than against TCPTP, but almost no inhibition against SHP-2.
Co-reporter:Ying Li;Miaoli Zhu;Qingming Wang;Caixia Yuan;Shu Xing;Xueqi Fu
BioMetals 2011 Volume 24( Issue 6) pp:993-1004
Publication Date(Web):2011 December
DOI:10.1007/s10534-011-9460-3
A series of copper complexes with multi-benzimidazole derivatives, including mono- and di-nuclear, were synthesized and characterized by Fourier transform IR spectroscopy, UV–Vis spectroscopy, elemental analysis, electrospray ionization mass spectrometry. The speciation of Cu/NTB in aqueous solution was investigated by potentiometric pH titrations. Their inhibitory effects against human protein tyrosine phosphatase 1B (PTP1B), T-cell protein tyrosine phosphatase (TCPTP), megakaryocyte protein tyrosine phosphatase 2 (PTP-MEG2), srchomology phosphatase 1 (SHP-1) and srchomology phosphatase 2 (SHP-2) were evaluated in vitro. The five copper complexes exhibit potent inhibition against PTP1B, TCPTP and PTP-MEG2 with almost same inhibitory effects with IC50 at submicro molar level and about tenfold weaker inhibition versus SHP-1, but almost no inhibition against SHP-2. Kinetic analysis indicates that they are reversible competitive inhibitors of PTP1B. Fluorescence study on the interaction between PTP1B and complex 2 or 4 suggests that the complexes bind to PTP1B with the formation of a 1:1 complex. The binding constant are about 1.14 × 106 and 1.87 × 106 M−1 at 310 K for 2 and 4, respectively.
Co-reporter:Qingming Wang, Liping Lu, Caixia Yuan, Kai Pei, Zhiwei Liu, Maolin Guo and Miaoli Zhu
Chemical Communications 2010 vol. 46(Issue 20) pp:3547-3549
Publication Date(Web):09 Apr 2010
DOI:10.1039/B925603B
A new dinuclear copper complex and several Cu-amino acid complexes inhibit protein tyrosine phosphatase 1B competitively at submicromolar levels, suggesting that copper complexes may interfere with cellular signaling pathways by inhibiting protein tyrosine phosphatases.
Co-reporter:Qi Ma, Miaoli Zhu, Caixia Yuan, Sisi Feng, Liping Lu and Qingming Wang
Crystal Growth & Design 2010 Volume 10(Issue 4) pp:1706-1714
Publication Date(Web):February 17, 2010
DOI:10.1021/cg901297y
Novel complexes of (half)-filled d-configurations, including [Zn(pdon)(SCN)(μ-Cl)(H2O)]n (1), [Cd2(pdon)2(μ1,3-SCN)4]n (2), [Hg(pdon)2Cl2] (3), and [Mn(pdon)2(SCN)2] (4) (pdon = 1,10-phenanthroline-5,6-dione), were synthesized and structurally characterized by single crystal X-ray diffraction. Self-assembly behaviors of these metal ions with anions are essentially different, although some of them are elements of the same group. Various supramolecular interactions of H-bonding, π···π stacking, and C−X···π (X = H, O, and S) are observed in the structures. In 1, central Zn2+ cations are connected to form an infinite one-dimensional (1D) zigzag chain by bridged Cl− and further extended to two-dimensional layers via weak interactions. Complex 2 consists of dinuclear units doubly bridged by two end-to-end (EE) SCN− anions and linked to 1D molecular helix along the b-axis with a long pitch of 13.077 Å. The helix displays racemic mixtures in the crystal. Complexes 3 and 4 are six-coordinated with distorted octahedron geometry. pdon serves as a terminal ligand in complexes. Spectroscopic and electrochemical properties of pdon and the complexes are studied in dimethyl sulfoxide (DMSO) solution at room temperature. Circular dichroism (CD) spectral results suggest that there is phenomenon of spontaneous resolution in the DMSO solution for the spiral structure 2.
Co-reporter:Qi Ma, Miaoli Zhu, Liping Lu, Sisi Feng and Tianwei Wang
Dalton Transactions 2010 vol. 39(Issue 25) pp:5877-5884
Publication Date(Web):26 May 2010
DOI:10.1039/C000940G
Three new coordination polymers ([Mn3(dctrz)2(H2O)8]n (1), [Co(Hdctrz)(H2O)3]n (2) and [Cd(Hdctrz)(H2O)2]n (3), H3dctrz, 1-H-1,2,4-triazole-3,5-dicarboxylic acid) based on the self-assembly of Mn2+, Co2+ and Cd2+ ions with H3dctrz have been synthesized and characterized by single crystal X-ray diffraction analysis. Variable temperature magnetic studies are investigated for complexes 1 and 2. Complex 1 is assembled into a one-dimensional molecular chain via trinuclear units formed from two dctrz anion bridges and eight coordination waters. In 2, the central Co2+ cations with six-coordinated octahedron geometry are bridged by Hdctrz anions to form one-dimensional zigzag chain structures. Complex 3 displays a 2D rhombus grid-like architecture with a (4, 4) topology, achieved through Hdctrz anion bridges. Both complexes 1 and 2 exhibit S = 5/2 (Mn2+) and S = 3/2 (Co2+) spin Heisenberg chains with alternating and regular magnetic sequences. Variable temperature (1.8–300 K) magnetic studies indicate weak antiferromagnetic coupling between the metal centres in complexes 1 and 2.
Co-reporter:Caixia Yuan, Liping Lu, Yanbo Wu, Zhiwei Liu, Maolin Guo, Shu Xing, Xueqi Fu, Miaoli Zhu
Journal of Inorganic Biochemistry 2010 Volume 104(Issue 9) pp:978-986
Publication Date(Web):September 2010
DOI:10.1016/j.jinorgbio.2010.05.003
Seven new mixed-ligand vanadyl complexes, [VIVO(5-Br-SAA)(NN)] and [VIVO(2-OH-NAA)(NN)] (1–7) (5-Br-SAA for 5-bromosalicylidene anthranilic acid, 2-OH-NAA for 2-hydroxy-1-naphthaldehyde anthranilic acid and NN for N,N′-donor heterocyclic base, namely, 2,2′-bipyridine (bpy, 1 and 5), 1,10-phenanthroline (phen, 2 and 6), dipyrido[3,2-d:2′,3′-f]quinoxaline (dpq, 3 and 7), dipyrido[3,2-a:2′,3′-c]phenazine (dppz, 4)), were synthesized and characterized. X-ray crystal structure of [VIVO(5-Br-SAA)(phen)] revealed a distorted octahedral geometry with the Schiff base ligand coordinated in a tridentate ONO-fashion and the phenanthroline ligand in a bidentate fashion. Density-functional theory (DFT) calculations suggest a similar structure and the same coordination mode for all the other oxovanadium complexes synthesized. Biochemical assays demonstrate that the mixed-ligand oxovanadium(IV) complexes are potent inhibitors of protein tyrosine phosphatase 1B (PTP1B), with IC50 values approximately 41–75 nM. Kinetics assays suggest that the complexes inhibit PTP1B in a competitive manner. Notably, they had moderate selectivity of PTP1B over T-cell protein tyrosine phosphatase (TCPTP) (about 2-fold) and good selectivity over Src homology phosphatase 1 (SHP-1) (about 4∼7-fold). Thus, these mixed-ligand complexes represent a promising class of PTP1B inhibitors for future development as anti-diabetic agents.A series of mixed-ligand vanadyl complexes [VIVO(5-Br-SAA)(NN)] and [VIVO(2-OH-NAA)(NN)] (NN = bpy, phen, dpq and dppz) were synthesized and characterized. All complexes show similar hexacoordinated distorted octahedral structures. The complexes have been found to be potent and moderately selective competitive inhibitors against human tyrosine phosphatase 1B (PTP1B) in vitro.
Co-reporter:Sisi Feng, Miaoli Zhu, Liping Lu, Lei Du, Yunbo Zhang and Tianwei Wang
Dalton Transactions 2009 (Issue 32) pp:6385-6395
Publication Date(Web):29 Jun 2009
DOI:10.1039/B900709A
A series of rationally designed pentanuclear clusters with D3 symmetry have been synthesized and structurally characterized. The complexes were of formula [Ni5L6]XnY4−n·mH2O [2–431, X = NO3, Y = OH, n = 1, m = 3 (5); X = Br, n = 4, m= 4 (6); X = I, n = 4, m= 0 (7)], where the ligand [L, (Z)-1,2-di(1H-benzoimidazol-2-yl)ethenol] was produced in situ under hydrothermal conditions. SEM images proved that the crystals of compounds 2–4, 6 and 7 were hollow tetragonal or hexagonal prisms, and a nucleation–dissolution–recrystallization mechanism was investigated. Complexes 3 and 4 demonstrated chirality from CD spectra. Magnetic susceptibility measurements of 4–7 showed the occurrence of antiferromagnetic interactions, and the all negative J values fitted of the variable-temperature magnetic susceptibility data applying the spin matrix method confirmed the overall antiferromagnetic exchange in the clusters.
Co-reporter:Caixia Yuan;Xiaoli Gao;Yanbo Wu
JBIC Journal of Biological Inorganic Chemistry 2009 Volume 14( Issue 6) pp:841-851
Publication Date(Web):2009 August
DOI:10.1007/s00775-009-0496-6
A series of oxovanadium complexes with mixed ligands, a tridentate ONO-donor Schiff base ligand [viz., salicylidene anthranilic acid (SAA)], and a bidentate NN ligand [viz., 2,2′-bipyridine (bpy), 1,10-phenanthroline (phen), dipyrido[3,2-d:2′,3′-f]quinoxaline (dpq), dipyrido[3,2-a:2′,3′-c]phenazine (dppz), or 7-methyldipyrido[3,2-a:2′,3′-c]phenazine (dppm)], have been synthesized and characterized by elemental analysis, electrospray ionization mass spectrometry, UV–vis spectroscopy, Fourier transform IR spectroscopy, EPR spectroscopy, and X-ray crystallography. Crystal structures of both complexes, [VIVO(SAA)(bpy)]·0.25bpy and [VIVO(SAA)(phen)]·0.33H2O, reveal that oxovanadium(IV) is coordinated with one nitrogen and two oxygen atoms from the Schiff base and two nitrogen atoms from the bidentate planar ligands, in a distorted octahedral geometry (VO3N3). The oxidation state of V(IV) with d1 configuration was confirmed by EPR spectroscopy. The speciation of VO–SAA–bpy in aqueous solution was investigated by potentiomtreic pH titrations, and the results revealed that the main species are two ternary complexes at a pH range of 7.0–7.4, and one is the isolated crystalline complex. The complexes have been found to be potent inhibitors against human protein tyrosine phosphatase 1B (PTP1B) (IC50 approximately 30–61 nM), T-cell protein tyrosine phosphatase (TCPTP), and Src homology phosphatase 1 (SHP-1) in vitro. Interestingly, the [VIVO(SAA)(bpy)] complex selectively inhibits PTP1B over the other two phosphatases (approximate ninefold selectivity against SHP-1 and about twofold selectivity against TCPTP). Kinetics assays suggest that the complexes inhibit PTP1B in a competitive and reversible manner. These suggest that the complexes may be promising candidates as novel antidiabetic agents.
Co-reporter:Sisi Feng, Miaoli Zhu, Liping Lu and Maolin Guo
Chemical Communications 2007 (Issue 45) pp:4785-4787
Publication Date(Web):10 Sep 2007
DOI:10.1039/B711695K
Single-crystal metal–organic microtubular architectures have been fabricated from designed D3 symmetrical nano clusters with a capped triple-helix pentanuclear M5O6 core under hydrothermal conditions.
Co-reporter:Caixia Yuan, Miaoli Zhu, Qingming Wang, Liping Lu, Shu Xing, Xueqi Fu, Zheng Jiang, Shuo Zhang, Zongwei Li, Zhuoyu Li, Ruiting Zhu, Ling Ma and Liqing Xu
Chemical Communications 2012 - vol. 48(Issue 8) pp:NaN1155-1155
Publication Date(Web):2011/11/25
DOI:10.1039/C2CC16818A
A dinuclear Cu(II) complex, [Cu2(μ-IDA)(phen)3(NO3)]NO3·4H2O (phen = 1,10-phenanthroline, H2IDA = iminodiacetic acid), was found to potently and selectively inhibit T-cell protein tyrosine phosphatase, and lead to the anti-proliferation and apoptosis of C6 glioma cells.
Co-reporter:Sisi Feng, Miaoli Zhu, Liping Lu and Maolin Guo
Chemical Communications 2007(Issue 45) pp:NaN4787-4787
Publication Date(Web):2007/09/10
DOI:10.1039/B711695K
Single-crystal metal–organic microtubular architectures have been fabricated from designed D3 symmetrical nano clusters with a capped triple-helix pentanuclear M5O6 core under hydrothermal conditions.
Co-reporter:Ya-Hui Liu, Li-Ping Lu, Miao-Li Zhu, Si-Si Feng and Feng Su
Dalton Transactions 2016 - vol. 45(Issue 22) pp:NaN9278-9278
Publication Date(Web):2016/04/29
DOI:10.1039/C5DT04953A
Three new Ni(II)-clusters based on a Y-shaped ligand (biphenyl-3,4′,5-tricarboxylate, H3BPT), [Ni5(HBPT)4(OH)2(H2O)12]n (1), [Ni4(BPT)2(OH)2(H2O)6]n·4nH2O (2), and [Ni7(BPT)2(1,4-bib)2(OH)6(HCO2)2]n·3nH2O (3) (1,4-bib = 1,4-bi(1H-imidazol-1-yl)benzene), have been synthesized under solvothermal conditions. They were studied by infrared spectroscopy (IR), single crystal X-ray diffraction, thermogravimetric analysis (TGA), and magnetochemistry. The complexes contain low nuclear Ni-clusters as building units (BUs). Structurally, in 1, the cluster BUs of [Ni5(μ3-OH)2]8+ can be viewed as two reverse triangles sharing a common vertex, which are connected by the partially deprotonated μ2–η1:η1-HBPT2− forming 1D chains. The BUs of [Ni4(μ3-OH)2]6+ clusters in 2 can be considered as two reverse triangles sharing a common edge and extended by deprotonated μ6–η1:η1:η1:η1:η2-BPT3− constructing a 2D framework. The 3D framework of complex 3 consists of a [Ni7(μ3-OH)4(R-COO)7(HCO2)3] cluster BUs with fully deprotonated μ5–η1:η1:η1:η1:η1:η1-BPT3− and 1,4-bib ligands. In addition, TGA reveals that the complexes are stable in the range of 293–548 K. Magnetostructural analyses indicate ferromagnetic coupling of J1 = 1.85(3) and J2 = 2.25(4) cm−1 in 1 and J = 5.76(6) cm−1 in 2, whereas magnetic parameters J1 = −2.64(3), J2 = −23.22(19) and J3 = 12.02(5) cm−1 indicate an alternating magnetic chain (AF/F) in 3.
Co-reporter:Qingming Wang, Liping Lu, Caixia Yuan, Kai Pei, Zhiwei Liu, Maolin Guo and Miaoli Zhu
Chemical Communications 2010 - vol. 46(Issue 20) pp:NaN3549-3549
Publication Date(Web):2010/04/09
DOI:10.1039/B925603B
A new dinuclear copper complex and several Cu-amino acid complexes inhibit protein tyrosine phosphatase 1B competitively at submicromolar levels, suggesting that copper complexes may interfere with cellular signaling pathways by inhibiting protein tyrosine phosphatases.
Co-reporter:Feng Su, Liping Lu, Sisi Feng, Miaoli Zhu, Zengqiang Gao and Yuhui Dong
Dalton Transactions 2015 - vol. 44(Issue 16) pp:NaN7222-7222
Publication Date(Web):2015/03/04
DOI:10.1039/C5DT00412H
To evaluate magnetic properties of isostructural compounds, a series of 3D carboxylate coordination polymers [M(H2bpta)]n, (H4bpta = 2,2′,4,4′-biphenyltetracarboxylic acid, M = Fe(II) (1), Ni(II) (2), Cu(II) (3) and Zn(II) (4)), was synthesized in H2O–CH3CN or H2O solvents, respectively. Structurally, complexes 1–4 have isostructural features with (5,5)-connected 3D framework, wherein the M(II) centre takes an octahedral coordination environment consisting of six oxygen atoms from carboxylates of ligands. The M(II) sites are linked by syn–anti carboxylates to form chains with an M⋯M separation of 4.880(2) (M = Fe), 4.784(2) (M = Ni), 4.541(2) (M = Cu), and 4.607(2) Å (M = Zn), respectively. The shortest M⋯M distances between interchains locate 9.122(4), 9.077(3), 9.361(3), and 8.767(2) Å, respectively. Magnetically, the isostructural polymers show different magnetic behaviors due to different spins of central ions. Theoretical analysis indicates that couplings between magnetic ions obey uniform chain models. The magnetic susceptibility of 1 and 2 are perfectly fitted by the modified Fisher model to yield an effective intra-chain exchange coupling constant of −0.81(1) and 3.67(2) cm−1, respectively. For 3, a Heisenberg ferromagnetic S = 1/2 chain included the intra-chain magnetic exchange interaction (J = 9.28(1) cm−1, and zj′ = −0.068(3) cm−1), weak ferromagnetic interactions in intra-chains, and weak antiferromagnetic interactions between interchains. The phenomena of 1–3 accord with the common view that the exchange interaction between two magnetic M(II) ions bridged by the syn–anti carboxylate bridge is dominantly weak ferro- or anti-ferromagnetic interactions. In addition, the M–O–C–O–M spin exchange interactions |J| of M2(CO2)2 (M = Mn(3d5)20, Fe(3d6), Co(3d7)20, Ni(3d8), Cu(3d9)) decrease in strength with Cu2(CO2)2 > Ni2(CO2)2 > Co2(CO2)2 > Fe2(CO2)2 > Mn2(CO2)2, consistent with orbit order.
Co-reporter:Qi Ma, Miaoli Zhu, Liping Lu, Sisi Feng and Tianwei Wang
Dalton Transactions 2010 - vol. 39(Issue 25) pp:NaN5884-5884
Publication Date(Web):2010/05/26
DOI:10.1039/C000940G
Three new coordination polymers ([Mn3(dctrz)2(H2O)8]n (1), [Co(Hdctrz)(H2O)3]n (2) and [Cd(Hdctrz)(H2O)2]n (3), H3dctrz, 1-H-1,2,4-triazole-3,5-dicarboxylic acid) based on the self-assembly of Mn2+, Co2+ and Cd2+ ions with H3dctrz have been synthesized and characterized by single crystal X-ray diffraction analysis. Variable temperature magnetic studies are investigated for complexes 1 and 2. Complex 1 is assembled into a one-dimensional molecular chain via trinuclear units formed from two dctrz anion bridges and eight coordination waters. In 2, the central Co2+ cations with six-coordinated octahedron geometry are bridged by Hdctrz anions to form one-dimensional zigzag chain structures. Complex 3 displays a 2D rhombus grid-like architecture with a (4, 4) topology, achieved through Hdctrz anion bridges. Both complexes 1 and 2 exhibit S = 5/2 (Mn2+) and S = 3/2 (Co2+) spin Heisenberg chains with alternating and regular magnetic sequences. Variable temperature (1.8–300 K) magnetic studies indicate weak antiferromagnetic coupling between the metal centres in complexes 1 and 2.
Co-reporter:Sisi Feng, Miaoli Zhu, Liping Lu, Lei Du, Yunbo Zhang and Tianwei Wang
Dalton Transactions 2009(Issue 32) pp:NaN6395-6395
Publication Date(Web):2009/06/29
DOI:10.1039/B900709A
A series of rationally designed pentanuclear clusters with D3 symmetry have been synthesized and structurally characterized. The complexes were of formula [Ni5L6]XnY4−n·mH2O [2–431, X = NO3, Y = OH, n = 1, m = 3 (5); X = Br, n = 4, m= 4 (6); X = I, n = 4, m= 0 (7)], where the ligand [L, (Z)-1,2-di(1H-benzoimidazol-2-yl)ethenol] was produced in situ under hydrothermal conditions. SEM images proved that the crystals of compounds 2–4, 6 and 7 were hollow tetragonal or hexagonal prisms, and a nucleation–dissolution–recrystallization mechanism was investigated. Complexes 3 and 4 demonstrated chirality from CD spectra. Magnetic susceptibility measurements of 4–7 showed the occurrence of antiferromagnetic interactions, and the all negative J values fitted of the variable-temperature magnetic susceptibility data applying the spin matrix method confirmed the overall antiferromagnetic exchange in the clusters.
Co-reporter:Sisi Feng, Fei Jia, Liping Lu, Zhongping Li and Shuo Zhang
Chemical Communications 2016 - vol. 52(Issue 23) pp:NaN4297-4297
Publication Date(Web):2016/02/19
DOI:10.1039/C6CC00399K
The first 32-membered Cu(II) cluster with a big cubic structure consisting of eight small cubic cores exhibited a high photocatalytic activity for the degradation of rhodamine B (∼99%) dye within 15 min under UV light irradiation, effective electrocatalytic activity for nitrite reduction and strong antiferromagnetic interactions among the Cu(II) centers.
![[1,1'-Biphenyl]-2,2',5,5'-tetracarboxylic acid](/data/chemimg/2292600/59795-47-0.png)
![[1,1'-Biphenyl]-2,2',5,5'-tetracarboxylic acid](/data/chemimg/2292600/59795-47-0_b.png)
![[1,1'-Biphenyl]-3,3',4,4'-tetracarboxylic acid](/data/chemimg/2200/22803-05-0.png)
![[1,1'-Biphenyl]-3,3',4,4'-tetracarboxylic acid](/data/chemimg/2200/22803-05-0_b.png)
