Synthesis,Crystal Structure and Gas Adsorption of a Two-fold Interpenetrated Three-dimensional Framework {[Cd(2-NO_2-BDC)(4,4?-DPA)]·(DMF)}_n

The reaction of Cd(NO_3)_2·4H_2O with 4,4?-dipyridylacetylene(4,4?-DPA) and 2-nitroterephthalic acid(2-NO_2-H_2BDC) in DMF/H_2O mixed solvent has afforded a compound {[Cd(2-NO_2-BDC)(4,4?-DPA)]·(DMF)}_n(1). Compound 1 has been characterized by single-crystal X-ray diffraction, powder X-ray diffraction, thermogravimetry analysis, and IR spectrum. Compound 1 crystallizes in the monoclinic system, space group P21/n, with a = 12.1488(3), b = 14.6689(3), c = 13.1615(3) ?, β = 111.809(3)o, V = 2177.63(9) ?~3, Z = 4, C_(23)H_(18)N_4O_7 Cd, M_r = 574.81, D_c = 1.753 g/cm~3, μ = 8.523 mm~(-1), F(000) = 1152, the final R = 0.0411 and wR = 0.1064 for 3589 observed reflections with I 2s(I). In compound 1, the Cd(Ⅱ) ions are linked by the carboxylate groups of 2-NO_2-BDC ligands to give a two-dimensional layered structure based on the centrosymmetric dinuclear Cd_2(COO)_2 units, which are further connected by the 4,4?-DPA ligands to produce a three-dimensional framework with pcu topology. Careful examination revealed that compound 1 is a 2-fold interpenetrating framework. Furthermore, the gas adsorption properties of 1 for N_2 and CO_2 have also been investigated.     

Coordination Assemblies of Cd~(Ⅱ) with 5-(Ethylthio)-1H-tetrazole and Halide Ions: Synthesis,Structure, and Luminescent Properties

Three cadmium(II)-halide complexes with 5-(ethylthio)-1H-tetrazole(Hett) as ligand, namely [Cd_7Cl_2(ett)_(12)(H_2O)_2]_n(1), [Cd_2(OH)Br(ett)_2]_n(2) and [Cd_2(OH)I(ett)_2]_n(3), have been hydrothermally synthesized and characterized. Complex 1 was synthesized at pH = 7 and exhibits a 3D supramolecular framework, where the adjacent Cd ions form a tetrahedron unit by ett ligands bridge and the tetrahedron units share vertices to connect each other by ett bridges to form a 2D layer architecture, which is further interlinked by μ_2-Cl to form 3D structures. Complexes 2 and 3 are isostructural, generated at pH = 8.0~9.0, displaying similar 2D networks via ett ligands and different halide ions(Br-in 2, I-in 3, respectively). In addition, thermal stabilities and luminescent properties of new complexes 1~3 have been studied.     

Syntheses,Structures and Catalytic Properties of Two Mn(Ⅱ) and Cd(Ⅱ) Coordination Polymers through in Situ Ligand Reaction

Two coordination polymers, namely [Mn(μ-Hcpia)(bipy)(H_2O)_2]_n(1) and [Cd_3(μ_3-Hcpia)_2(μ-Hbiim)_2(μ-H_2biim)(H_2O)_2]_n(2), have been constructed hydrothermally using H_2cbia(H_2cbia = 5-(4'-cyanobenzoxy)isophthalic acid), bipy(bipy = 4,4'-bipyridine), H_2biim(H_2biim = 2,2'-biimidazole), and manganese or cadmium chlorides at 160℃. Interestingly, the H_3cpia(H_3cpia = 5-(4'-carboxylphenoxy)isophthalic acid) ligand was generated by in situ hydrolysis of cyano group in H_2cbia. The products were isolated as stable crystalline solids and were characterized by IR spectra, elemental analyses, thermogravimetric analyses(TGA), and single-crystal X-ray diffraction analyses. Both compounds crystallize in the triclinic system, space group P1. Compound 1 discloses a 1D linear chain of the 2C1 topological type. Adjacent chains are assembled into a 2D supramolecular sheet through O–H···O/N hydrogen bonds. Compound 2 features a 3D framework with a 3,4,4 T25 topology. The luminescent and catalytic properties of two compounds were investigated. Compound 1 exhibits a superior catalytic activity in the cyanosilylation at room temperature.     

Two Coordination Polymers Constructed by Cd(Ⅱ) and Zn(Ⅱ) with in situ Generated 5-(3-Pyridyl)tetrazolate Ligand:Syntheses,Crystal Structures and Luminescence Properties

Hydrothermal reactions of 3-cyanopyridine and Na N3 with Zn Cl_2 or Cd Cl_2·5/2H_2 O in the presence of 1,4-benzenedicarboxylic acid(H2bdc) yielded two new coordination polymers,{[Zn(3-ptz)(bdc)_(0.5)(H_2O)_2]n·2H_2O}_n(1) and [Cd_2(3-ptz)_2Cl_2]_n(2),based on in situ synthesized 5-(3-pyridyl)tetrazolate(3-ptz-) organic ligand.They have been structurally characterized by elemental analysis(EA),infrared spectroscopy(IR) and single-crystal/powder X-ray diffraction(PXRD).In 1,two Zn(Ⅱ) ions are linked together through two μ_2-(3-ptz-) ligands to form a dimeric unit of [Zn(μ_2-3-ptz)(H_2O)_2]_2~(2+),which is further connected with other equivalent units by μ_2-bdc~(2-)spacers,resulting in an infinite 1D polymeric chain of [Zn_2(3-ptz)_2(H_2O)_2(bdc)]_n,and then strong hydrogen bonding interactions extend these 1D chains into a 3D supramolecular structure.In 2,the Cd(Ⅱ) ions are connected through μ_4-(3-ptz-) ligands and Cl-anions,leading to infinite 2D layers of [Cd_2(3-ptz)Cl_2]_n~(n+),which are further linked by another μ_4-(3-ptz-) pillared ligand to form a 3D layered-pillared framework architecture of [Cd)2(3-ptz))2Cl)2])n.Furthermore,thermal stability of these compounds was measured by thermogravimetric analysis(TGA) and their photoluminescent properties were also investigated in the solid state at room temperature.     

A(3,4)-Connected 3D Heteronuclear Framework with Three Kinds of Discrete Cadmium(Ⅱ) Ions: Synthesis,Crystal Structure and Luminescence Property

A novel 3D hetero-nuclear framework,namely [K_2Cd_5(Hbptc)_4(H_2O)_(12)·12H_2O]_n(1,H4 bptc = biphenyl-2,3,3?,5?-tetracarboxylic acid),was obtained by hydrothermal reaction. X-ray singlecrystal structure analysis reveals that polymer 1 crystallizes in orthorhombic,space group Pbcn with a = 26.6152(13),b = 11.7449(5),c = 29.5923(14) ?,V = 9250.3(7) ?~3,C_(64)H_(76)Cd_5K_2O_(56),Mr = 2381.44,Dc = 1.710 g/cm~3,μ(MoK α) = 1.323 mm~(-1),F(000) = 4744,Z = 4,the final R = 0.0668 and wR = 0.1135 for 10613 observed reflections(I 2σ(I)). Polymer 1 displays a 3D network that is built on the unprecedented heterobimetallic [Cd_3Cd_2K] molecular building block with a(3,4)-connected(6·8·8)2(6·6·82·82·126·126) topology which represents a rare 2-fold interpenetrating 3D framework topology network. The luminescence analyses reveal that polymer 1 shows obvious emission at room temperature in the solid state. In addition,it was also characterized by elemental,IR spectra and TG analyses.     

Three Novel Luminescent Zinc(Ⅱ) Compounds Constructed by Employing Mixed-ligand Strategy

Three novel coordination polymers,[Zn(suc)(o-bix)]_n (1),[Zn(suc)(m-bix)·H_2O]_n (2) and[Zn_2(suc)_2(p-bix)_2·4H_2O]_n (3)(H_2suc=succinic acid,o-bix=1,2-bis(imidazol-1-ylmethyl)-benzene,m-bix=1,3-bis(imidazol-1-ylmethyl)-benzene,p-bix=1,4-bis(imidazol-1-ylmethyl)-benzene),have been synthesized and structurally characterized by elemental analysis,IR spectroscopy,thermogravimetric analysis,powder X-ray diffraction,and single-crystal X-ray diffraction.These three coordination polymers present various structures originated from auxiliary N-donor ligands with different configurations.Compound 1 shows a 2D network with4~4-sql topology.Compound 2 exhibits an infinite chain,and the adjacent chains are extended into a 2D sheet byπ-πstacking interactions.Changing the conformation of the N-donor ligand leads to 3 featuring a 3D framework with a novel 4-connected (6~5·8) topology.In addition,the solid-state photoluminescent properties of compounds 1～3 are investigated.     

Synthesis,Crystal Structure and Properties of a 3-Fold Interpenetrating 3D Cd(Ⅱ) Complex Derived from 4-(2-Methyl-1H-imidazol-1-yl)benzoic Acid

A new Cd~Ⅱ coordination complex,namely [Cd(iba)_2]_n(1),was prepared by the hydrothermal reaction of Cd(NO_3)_2·4H_2O with 4-imidazol-1-yl-benzoic acid(Hiba). Single-crystal X-ray diffraction analysis shows that compound 1 crystallizes in monoclinic system,space group Cc with a = 11.403(4),b = 30.480(9),c = 7.732(3) ?,β = 130.189(4)o,V = 2503.0(1) ?~3,Z = 4,C_(22)H_(18)CdN_4O_4,Mr = 514.80,Dc = 1.666 g/cm~3,F(000) = 1032 and μ(Mo Kα) = 1.101 mm-1. The final R and wR are 0.0573 and 0.1823 for 4421 observed reflections with I 2σ(I). Each iba-ligand coordinates in a bidentate fashion,connecting the Cd(Ⅱ) atoms to form a 2D wave-shape layer structure,which can be simplified as a four-connected topological net. Interestingly,the 2D layers are further extended into a 3-fold interpenetrating 3D architecture. Compound 1 displays an emissive maximum at 455 nm in the solid state at room temperature and a response of the second harmonic generation(SHG) activity is approximately 0.8 times that of KDP.     

A Pair of 3D Homochiral Coordination Polymers with Open Channels Constructed by Lactic Acid Derivative Ligands and In-situ Formed Anions

With the help of in-situ formed CH_3COO~- anion, a pair of 3D homochiral coordination polymers with open channels were constructed by the assembly of lactic acid derivative ligands, 1.4-DIB ligands and Cd(II) ions, namely [Cd_3((R)-CIA)_2(CH_3CO_2)_2(1.4-DIB)_2(H_2O)_2]·x(Guest)(1-D) and [Cd_3((S)-CIA)2(CH_3CO_2)_2(1.4-DIB)_2(H_2O)_2]·x(Guest)(1-L). They contain 1D interesting ladder-like Cd-(R)-CIA~(3-) chains and exhibit SHG-active behavior and photoluminescent property.     

Crystal Structures,Luminescent Properties and Hirshfeld Surface Analyses of Zn(Ⅱ) and Cd(Ⅱ) Compounds Based on 1-(2-Carboxyl-phenyl)-3-(pyridin-2-yl)pyrazole

Two compounds,[Zn_2(Hcppp)_2(cppp)_2(H_2O)_2]·2 NO_3·6 H_2O(1) and [Cd(Hcppp)_2Cl_2]· 3H_2O(2)(Hcppp = 1-(2-carboxyl-phenyl)-3-(pyridin-2-yl)pyrazole),are synthesized and characterized by IR,TGA and X-ray single-crystal/powder diffraction.Compound 1 crystallizes in monoclinic system,space group P2_1/c with a = 9.894(2),b = 15.856(3),c = 20.430(4) ?,β = 101.70(3)°,V = 3138.5(11) ?~3,Z = 2,M_r = 1457.94,D_c = 1.543 g/cm~3,F(000) = 1504,R = 0.0278 and wR = 0.0749 for 6157 observed reflections(I 2σ(I)).Compound 2 crystallizes in triclinic system,space group P1 with a = 9.1424(4),b = 11.6427(5),c = 16.1345(7) ?,α = 102.6430(10)°,β = 95.4530(10)°,γ = 104.0060(10)°,V = 1605.94(12) ?~3,Z = 2,M_r = 767.88,D_c = 1.588 g/cm~3,F(000) = 776,R = 0.0307 and wR = 0.0764 for 6275 observed reflections(I 2σ(I)).Compound 1 exhibits a binuclear structure while compound 2 shows a mononuclear structure.In compound 1,two cppp-ligands display the μ_2-kN,N′:k O and two Hcppp ligands show the μ_1-kN,N′ coordination modes.However,two Hcppp ligands connect one Cd(Ⅱ) cation and exhibit the μ_1-kN,N′ binding mode in compound 2.The compounds are both studied using Hirshfeld surface analyses and 2D fingerprint plots.The luminescent properties are also discussed.     

Hydrothermal Synthesis,Crystal Structure and Luminescent Property of a Cd(Ⅱ) Compound with(4,6)-Connected Topology

A new Cd(Ⅱ) coordination polymer, namely {Cd_2(L)(biimpy)(H_2O)}_n(1, H4 L = 3-(3?,5?-dicarboxylphenoxy)phthalic acid, biimpy = 2,6-bis(1-imdazoly)pyridine), has been successfully synthesized via the hydrothermal reactions of Cd(Ⅱ) ions, H_4L and biimpy. The crystal structure is of triclinic, space group P1 with a = 7.7874(5), b = 9.9716(5), c = 18.5278(6) ?, α = 91.327(4), β = 96.689(4), γ = 111.896(5)o, V = 1322.39(12) ?~3, C_(27)H_(17)Cd_2N_5O_(10), M_r = 796.26, Z = 2,D_c = 2.000 g/cm~3, F(000) = 780, μ = 1.679 mm~(-1), R = 0.0345 and wR = 0.0767 for 3890 observed reflections(I 2s(I)). Single-crystal X-ray structural analysis reveals that compound 1 features a three-dimensional(3D) framework based on two different dinuclear [Cd_2(COO)_2] building subunits, and topological analysis shows that it can be simplified into a binodal(4,6)-connected topological network with the point symbol of {3.4~2.5~2.6}{3~2.4~2.5~2.6~4.7~4.8}. Moreover, the thermal stability and luminescent property of compound 1 were also studied.     

Organic Carboxylate Ligand Tuned Topological Variations in Three Zn(Ⅱ) Coordination Polymers: Syntheses,Crystal Structures and Photoluminescent Properties

Three new Zn(Ⅱ) coordination polymers, namely [Zn_2(suc)_2(bib)_2]_n·nH_2 O(1), [Zn(glu)(bib)]_n·4 nH_2 O(2), and [Zn(adp)(bib)]n(3)(bib = 1,4-bis(N-imidazolyl)butane, H_2 suc = succinic acid, H_2 glu = glutaric acid, H_2 adp = adipic acid) have been hydrothermally synthesized and structurally characterized. Compound 1 features a 3D framework with 4-connected hxg-d topological network, compound 2 is comprised of 2D 4~4-sql-type sheets, and the adjacent 2D sheets are further packed into a 3D supramolecular architecture via intermolecular hydrogenbonding interactions, and compound 3 is a 3D framework with 4-fold interpenetrating dia topology. The structural comparison of these three compounds demonstrates that the topological variations can be well controlled by employing aliphatic dicarboxylate ligands with different spacer lengths. Moreover, the thermal stabilities and photoluminescent properties of them were also studied in detail.     

A One-dimensional Cd(Ⅱ) Coordination Polymer Constructed from 1,4-Benzene-dicarboxylic Acid and 3-(2,6-Di(pyrazin-2-yl)pyridin-4-yl)-1H-indole:Synthesis,Structure and Photoluminescence

A new coordination polymer {[Cd(C_(21)H_(14)N_6)(C_8H_4O_4)]·H_2O}_n(1) was synthesized by an elaborate design via the reaction of 3-(2,6-di(pyrazin-2-yl)pyridin-4-yl)-1H-indole(bppi),1,4-benzene-dicarboxylic acid(H2bdc) and cadmium(Ⅱ) nitrate in CH_3OH/H_2O mixed solvents. Complex 1 crystallizes in orthorhombic,space group Ccca with a = 20.012(4),b = 31.881(6),c = 19.808(4) ?,V = 12638(4) ?~3,Z = 16,C_(29)H_(20)CdN_6O_5,M_r = 644.91,D_c = 1.356 g·cm~(-3),μ = 0.735 mm~(-1),F(000) = 5184,GOOF = 1.046,the final R = 0.0405 and wR = 0.1063 for 6870 observed reflections(I 2σ(I)). The Cd(Ⅱ) centre is hepta-coordinated by three N and four O atoms from one bppi terminal ligand and two bdc2– ligands,respectively,displaying a capped trigonal prism geometry. Structure extension gives coordination polymeric chains,in which the bdc2– linkers connect Cd(Ⅱ) cations into a one-dimensional(1D) coordination polymer along the c axis,giving zigzag chains with the Cd···Cd separation of 11.178(1) ?. The adjacent bppi terminal ligands in the chains are anti-periplanar conformation. The three-dimensional(3D) structure is stabilized by π···π stacking and hydrogen-bonding interactions to form a supramolecular self-penetrating network with 1D channels. In 1,there are voids 2999.7 ?~3 with 23.7% of per unit cell volume. Thermal analysis indicates that the framework of 1 is stable until 651 K and the photoluminescence of 1 in the solid shows very weak fluorescence at 382 and 560 nm upon excitation at 310 nm.     

Synthesis,Crystal Structure and Fluorescent Properties of a Cadmium(Ⅱ) Complex with 3-(Pyridin-4-yl)-5-(pyrazin-2-yl)-1H-1,2,4-triazole

Compound [Cd_(1.5)(ppt)Br_2(H_2O)]_(2n)(1),where Hppt = 3-(pyridin-4-yl)-5-(pyrazin-2-yl)-1H-1,2,4-triazole,has been synthesized under hydrothermal conditions and characterized by elemental analysis,IR spectra,powder XRD,and X-ray diffraction.Compound 1 crystallizes in the triclinic system,space group P1 with a = 7.4402(6),b = 8.0570(7),c = 12.8674(11) ?,α = 89.7300(10),β = 89.8570(10),γ = 68.3910(10)°,V = 717.13(10) ?3,Z = 1,Dc = 2.638 g/cm3,μ = 7.824 mm~(-1),F(000) = 534,the final R = 0.0324 and w R = 0.1084 for 2324 observed reflections with I 2σ(I).X-ray diffraction analyses revealed that complex 1 is a 2D layered coordination polymer constructed from the linkage of [Cd_3(μ-Br)_4] trinuclear units with ppt-spacers,and a 3D supramolecular architecture is further assembled in 1 via hydrogen-bonding contacts.Fluorescence measurements show that 1 has medium fluorescent emission at 450 nm.     

A New Cd(Ⅱ) Coordination Polymer Constructed by 3-(2-Pyridyl)pyrazole and 5-Nitroisophthalic Acid:Synthesis,Crystal Structure and Theoretical Calculations

A new coordination polymer, [Cd_2(NIPH)(L)_2(H_2O)]n(1, HL = 3-(2-pyridyl)pyrazole and H_2NIPH = 5-nitroisophthalic acid), has been synthesized. The structure of complex 1 has been characterized by X-ray single-crystal diffraction, elemental analysis, IR spectrum analysis, thermogravimetric analysis and fluorescence spectrum analysis. Complex 1 belongs to the triclinic system, space group P1 with a = 8.9539(6), b = 11.6252(8), c = 12.2472(8) ?, α = 80.011(2), β = 80.3850(10), γ = 86.773(2)°, V = 1237.37(14) ?~3, Z = 2, D_c = 1.987 g/cm~3, μ = 1.780 mm~(-1), M_r = 740.25, F(000) = 724, the final R = 0.0295 and wR = 0.1015 with I 2σ(I). Two H_2NIPH as monodentate and bidentate ligands and two L ligands link four Cd(Ⅱ) ions to form a tetranuclear subunit. Each pair of the tetranuclear subunits is bridged by NIPH ligands to yield a one-dimensional double-chain structure. Furthermore, the 1D chains are linked into a 3D supramolecular framework with hydrogen bonds and π-π interactions. In addition, we analyzed Natural Bond Orbital(NBO) in using the PBE0/LANL2DZ method built in Gaussian 03 Program. The calculation results indicated the obvious covalent interaction between the coordinated atoms and Cd(Ⅱ) ion.     

A New Two-dimensional Cd(Ⅱ) Complex Assembled by 1,3,5-Benzenetricarboxylic Acid and 3-(2-Pyridyl)pyrazole

A new 2D coordination polymer, {[Cd_5(BTC)_2(L)_4(H_2O)_2]_n·2H_2O}_n(1, H_3BTC = 1,3,5-benzenetricarboxylic acid, HL = 3-(2-pyridyl)pyrazole) was synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction, powder XRD, IR, TGA, fluorescence spectrum and elemental analysis techniques. Complex 1 belongs to the monoclinic system, P2_(1/c) space group, with a = 8.8732(4), b = 17.5179(7), c = 17.8123(7) ?, β = 103.1830(10)°, V = 2695.77(19) ?~3 and Z = 2. It features a 2D network constructed by BTC and L ligand. In addition, we analyzed Natural Bond Orbital(NBO) by using the PBE0/LANL2DZ method built in Gaussian 09 Program. The calculation results indicated obvious covalent interactions between the coordinated atoms and Cd(Ⅱ) ion.     

Syntheses,Structures and Luminescent Properties of the Cadmium(Ⅱ) Complex with 3,3?-Thiodipropionic Acid

One new luminescent material of complex {[Cd(DPA)(H_2O)_2]·(H_2O)_2}_n(1) was synthesized by evaporation methods using 3,3?-thiodipropionic acid(DPA) and cadmium nitrate as the starting materials. Compound 1 crystallizes in the monoclinic system,space group P2_1/n with a = 7.5460(7),b = 13.372(3),c = 12.304(3) ?,β = 95.95(3)o,V = 1234.8(4) ?~3,D_c = 1.940 g/cm~3,C_6H_(16)O_8 SCd,M_r = 360.65,F(000) = 720,μ(Mo Ka) = 1.960 mm~(-1),Z = 4,R = 0.0460 and wR = 0.1185 for 1835 observed reflections(I 2σ(I)),and R = 0.0591,wR = 0.1245 for all data. The complex has been characterized by elemental analysis,FT-IR,TG,PXRD and X-ray single-crystal structure analysis and the fluorescence property has also been studied. As a result,complex 1 possesses a two-dimensional(2-D) structure through DPA ligands interconnecting Cd2+ ions. Complex 1 emits the intense fluorescence of 420 nm in the solid state at room temperature.     

Synthesis,Structure and Luminescent Properties of a Two-dimensional Cobalt(Ⅱ) Coordination Polymer Based on 2-Thiobarbituric Acid

A two-dimensional coordination polymer [Co(H_2tba)_2(DMF)_2]_n 1(H_2tba = 2-thiobarbituric acid anion, DMF = N,N-dimethylformamide) has been synthesized by Co Cl2·6H2O with the 2-thiobarbituric acid ligands under solvothermal conditions. Compound 1 was further characterized by FTIR, elemental analysis, TGA and powder XRD techniques. Single-crystal X-ray diffraction studies revealed that the title compound crystallizes in the monoclinic space group Pbca with a = 12.5948(12), b = 11.4269(11), c = 14.8939(15) ?, V = 2143.5(4) ?~3, Z = 4, Dc = 1.523 g·cm-3, F(000) = 1012, μ = 1.038 mm~(-1), R = 0.0358 and w R2 = 0.0888(I 2σ(I)). Single-crystal X-ray diffraction analysis reveals that 1 is the first two-dimensional noninterpenetrating(4, 4) net coordination polymer based on the 2-thiobarbituric acid. Coordination polymer 1 exhibits two luminescent emission spectra at 477 and 489 nm with the excitation peak at 273 nm.     

A Double Azole-bridged Dinuclear Copper(Ⅱ) Complex Containing 4-Pyridyl-NH-1,2,3-triazoles: Synthesis,Structure and Magnetism

A new dinuclear copper(Ⅱ) compound [Cu_2(CH_3COO)_2(L)_2(H_2O)_2]·4H_2O(1, HL = 4-pyridyl-NH-1,2,3-triazole) has been synthesized and characterized. Single-crystal X-ray diffraction showed that complex 1 crystallizes in monoclinic space group P2_1/c with a = 0.8427(1), b = 1.0981(1), c = 1.3610(1) nm, β = 93.364(4)°, V = 1.2573(1) nm~3, M_r = 643.56, Z = 2, D_c = 1.700 g/cm~3, μ = 1.760 mm~(-1), R = 0.0376, wR = 0.0981, and possesses a planar Cu_2N_4 six-membered ring, in which both Cu(Ⅱ) ions are bridged by two 1,2,3-triazole ligands. The neighboring dinuclear molecules are bound by strong intermolecular hydrogen bonds to create 1-D chains expanding along the b axis, which further form a 3-D supramolecular framework. Magnetic susceptibility measurement indicated the presence of weak antiferromagnetic interactions within the complex. The best fit using spin Hamiltonian yields the magnetic coupling constant J = –14.82 cm~(-1) above 30 K. The magnetic data are compared to those obtained for related double diazine bridged dinuclear copper(Ⅱ) complexes and magnetostructural correlations are discussed.     

Effect of pH/Auxiliary Ligand on the Structures of Coordination Compounds Based on a Novel Ligand 2,6-Bis(pyrazin-2-yl)pyridine-4-carboxylate

Four new coordination compounds, [Zn(bppc)_2(H_2O)_2]·3 H_2O(1), [Zn2(bppc)2(mbdc)(H_2O)4]·7 H_2O(2), [Zn(bppc)2(H_2O)2]n·n(m-Hbdc)·n(H_2O)(3), [Zn2(bppc)(btc)(H_2O)3]n·5 n H_2O(4)(Hbppc = 2,6-bis(pyrazin-2-yl)pyridine-4-carboxylate, H2(m-bdc) = 1,3-benzenedicarboxylic acid, H3 btc = 1,3,5-benzene-tricarboxylic acid), have been hydrothermally synthesized and structurally characterized. Compound 1 shows a mononuclear structure and 2 shows a dinuclear structure. Compound 3 is a one-dimensional chain structure, which is extended into a 3D supramolecular network by intermolecular hydrogen interactions. In 4, a 1D loop-like chain is connected by(btc)3-anions to generate a 2D layer structure. The structure differences of 1~4 show that the p H and aromatic acid as auxiliary ligand have important influence on the final structures.iAdditionally, the luminescent properties of 1~4 have been investigated with fluorescent spectra in the solid state, and 1~4 display a strong fluorescent emission at room temperature and have potential applications as fluorescent-emitting materials.     

Solvothermal Synthesis,Crystal Structure and Luminescent Property of a Two-dimensional Lead(Ⅱ) Compound:[Pb(bmzbc)_2]_n

A two-dimensional coordination polymer, [Pb(bmzbc)_2]_n(1)(Hbmzbc =4-benzimidazole-1-yl-benzoic acid), has been synthesized by the solvothermal reaction of Pb(NO_3)_2 with Hbmzbc at 120 ℃ in ethanol solvent. Compound 1 has been characterized by single-crystal X-ray diffraction, powder X-ray diffraction, thermogravimetry analysis, and IR spectrum. Compound 1 crystallizes in the orthorhombic system, space group Pccn, with a = 12.5801(7), b = 20.0795(11), c = 9.1830(6) ?, V = 2319.6(2) ?~3, Z = 4, C_(28)H_(18)N_4O_4Pb, M_r = 681.65, D_c = 1.952 g/cm~3, μ = 7.319 mm~(-1), F(000) = 1312, the final R = 0.0336 and wR = 0.0965 for 1699 observed reflection with I 2σ(I). In 1, the bmzbc~– ligands bridge the Pb(Ⅱ) ions to generate a 2-D sheet with(4, 4) topology. The complex exhibits turquoise photoluminescent emission with a maximum at 480 nm upon excitation at 300 nm.