Mei-Li Zhang

Syntheses, crystal structures, and photoluminescent properties of two new Cd(II) coordination polymers based on biphenyl-2,2′,4,4′-tetracarboxylate and dipyridyl-containing ligands

Two new Cd(II) coordination polymers, [Cd2(btc)(dpe)1.5(H2O)]n (1) and [Cd2(btc)(bpp)(H2O)]n (2), were prepared by the hydrothermal reaction of cadmium nitrate with H4btc (H4btc = biphenyl-2,2′,4,4′-tetracarboxylic acid) in the presence of 1,2-di(4-pyridyl)ethylene (dpe) and = 1,2-bis(4-pyridyl)propane (bpp), respectively, structurally characterized by single-crystal X-ray diffraction, and further characterized by elemental analysis, IR spectroscopy, and thermogravimetric analysis. In 1, btc4− connect six Cd2+ ions, forming a 3-D (3,3,6)-connected [Cd2(btc)] net, and further connected by 1-D [Cd(dpe)]n chains to construct the final (4,5,6)-connected (42.52.65.7)(43.62.7)(45.53.64.72.8) net. In 2, a 3-D [Cd2(btc)] net is also constructed from btc4− connecting six Cd2+ ions, giving a 3-D (3,4,7)-connected network. The overall structure of 2 can be regarded as a (4,4,6)-connected (45.64) (42.5.62.8) (43.54.67.7) framework with bpp linking adjacent Cd ions. Structural comparisons show that the secondary auxiliary N-donors have important effects on the final structure and properties. Photoluminescent properties of 1 and 2 are also discussed.

Synthesis, characterization, and crystal structures of two Ag (I) coordination polymers based on biphenyl-2,2′,4,4′-tetracarboxylate

In this article, [Ag8(btc)2(2,2′-bpy)2] n (1) and [Ag4(btc)(phen)2] n (2) (H4btc = biphenyl-2,2′,4,4′-tetracarboxylic acid, 2,2′-bpy = 2,2′-bipyridine, phen = 1,10-phenanthroline) have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR spectra, thermogravimetric analyses, and single-crystal X-ray diffraction. Complex 1 shows a 3-D framework containing a 2-D bilayer network constructed from (btc)4− with Ag (I), whereas 2 features a 2-D supramolecular bilayer network. The differences of the two complexes demonstrate that nitrogen-containing chelating ligands have a significant effect on the formation and structure of the resulting complexes. Electrochemistry properties of 1 were also studied.

Syntheses, crystal structures, and luminescence of two new coordination polymers based on biphenyl-2,2′,4,4′-tetracarboxylate

Two new coordination polymers, [Zn(H2btc)(4,4′-bpy)2] n (1) and {[Cd(H2btc) (terpy)] · H2O} n (2) (H4btc = biphenyl-2,2′,4,4′-tetracarboxylic acid, 4,4′-bpy = 4,4′-bipyridine, terpy = terpyridine), have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR spectra, and single-crystal X-ray diffraction. Complexes 1 and 2 are 1-D chains linked through partially deprotonated H4btc. The adjacent 1-D chains of 1 are further formed into 2-D supramolecular architecture through inter-chain N–H···O hydrogen bonds. In contrast, due to a different auxiliary ligand, the 1-D chains of 2 are further extended into 3-D supramolecular framework through inter-chain O–H···O hydrogen bonds. Thermal stabilities and luminescence of 1 and 2 were also studied.

Coordination polymers constructed from an asymmetric dicarboxylate and N-donors: preparation, characterization, and properties

Two new coordination polymers with an asymmetric dicarboxylate and 4,4′-bipyridine ligand, {[Co(bpy)(H2O)4]·(cpa)·0.5H2O}n (1) and {[Ag(cpa)(bpy)][Ag(bpy)]·4H2O}n (2) (H2cpa = 4-(2-carboxyethyl)benzoic acid, bpy = 4,4′-bipyridine), have been hydrothermally synthesized and characterized by elemental analysis, FT-IR spectroscopy, and single-crystal X-ray diffraction. Compound 1 displays a linear chain with guest molecule (cpa)2− ions existing in the structure. Compound 2 contains two independent units, [Ag(cpa)(bpy)]– (A) and [Ag(bpy)]+ (B), which form a 1-D + 1-D structure. A shows a 1-D chain structure bearing hooks formed by the carboxylates and organized into a tubular structure by hydrogen-bonding interactions. B has linear chains formed from Ag+ and bpy. The A and B chains co-crystallize with waters of crystallization to provide two linear [Ag(bpy)]+ chains embedded in the tubular structure formed by A via π…π stacking contacts. In 1 and 2, hydrogen-bonding and π…π stacking interactions connect the discrete 1-D chains into 3-D supramolecular structures. The fluorescent properties, TG analysis, and X-ray powder diffraction patterns for 1 and 2 were also measured.

Structural assembly from 1D to 3D motivated by the linear co-ligands, and the magnetic and photocatalytic properties of five NiII coordination polymers with 5-(4′-carboxylphenyl)nicotinic acid

Five novel nickel(II) coordination polymers, namely, [Ni(cpna)(4,4′-bipy)(H2O)2] (1), [Ni(cpna)(1,4-bbi)(H2O)]·H2O (2), [Ni4(cpna)4(H2O)8] (3), [Ni2(cpna)2(4,4′-bbpy)(H2O)] (4), and [Ni (cpna)(1,4-bibz)0.5(H2O)]·H2O (5) (H2cpna = 5-(4′-carboxylphenyl)nicotinic acid; 4,4′-bipy = 4,4′-bipyridine; 1,4-bbi = 1,4-bisbenzimidazole; 4,4′-bbpy = 4,4′-bis(imidazol-1-ylmethyl)biphenyl; 1,4-bibz = 1,4-bis(1-imidazoly)benzene), have been synthesized under hydrothermal conditions based on H2cpna and four different linear N-donor co-ligands. Structural analyses show that all Ni(II) ions lie in slightly distorted six coordinated octahedral geometries. Complexes 1–5 exhibit a variety of architectures: 1 features a 1D chain structure, complex 2 possesses a 2D network, and compounds 3–5 display a 3D framework with dimer Ni2 units, which might be affected by the coordination modes and lengths of the co-ligands. The magnetic and photocatalytic properties were investigated. The variable-temperature magnetic susceptibilities indicate that weak ferromagnetic interactions exist between two adjacent Ni(II) ions of 2, while the other compounds show antiferromagnetic exchange interactions. All of them could accelerate the degradation rate of MO under visible light irradiation, especially compound 2.

Crystal structure of catena-aquatris(1H-imidazole-N)(μ-sulfato)copper(II), Cu(H2O)(C3H4N2)3(SO4)

C9H14Q1N6O5S, monoclinic, P12i/nl (no. 14), a = 11.723(2) Ä, b = 8.651(2) A, c = 13.839(3) Ä, β = 91.703(4)°, V= 1402.8 A, Ζ = 4,R&(F) = 0.046, wRnffF) = 0.133, Τ = 296 Κ. Source of material The title complex was synthesized by mixed solution method. A solution of CuSC>4 · 5H2O (0.125 g, 0.5 mmol) in 10 ml methanol was added to a solution of Ι,Γ-carbonyl-diimidazole (0.081 g, 0.5 mmol) in 10 ml methanol. The reaction mixture was stirred for 2 h at room temperature and then filtered. The filtrate was diffused in ether. After two weeks, blue block-shaped crystals were obtained. Discussion Helical structures have received much attention in coordination chemistry and materials chemistry because helicity is an essential feature of life and also important in advanced materials such as optical devices and asymmetric catalysis [1,2]. Consequently, many single-, doubleand higher-order stranded helical complexes have been generated by self-assembly processes [3,4]. Herein, we report a novel ID helical chain coordination polymer [Cu(C3H4N2)3(H20XS04)]„. In the crystal structure of title compound (figure, top), the Cu(II) atoms are coordinated by three Ν atoms from three different imidazole ligands (d(Cu—Nl) = 1.998(3) Ä, d(Ca—N3) = 1.984(3) A, d(Cu—N5) = 1.997(4) Ä. Imidazole molecules resulted from Ι,Γ-carbonyl-diimidazole which was easily hydrolyzed in methanol solution. Furthermore, three Ο atoms from two sulfato groups (d(Cu—Ol) = 2.003(3) Ä, d(Cu—02A) = 2.534(4) Ä) and one water molecule (d(Cu—Ol) = 2.551(5) Ä) furnish a distorted octahedral environment. The cisoid and transoid bond angles around the Cu atoms fall in the regions of 85.6(2)° 92.1(2)° and 176.6(2)° -178.1(2)°, respectively. Each pair of adjacent Cu (Π) atoms are bridged by a bidentate sulfato group to form a ID single helical chain running along a crystallographic 2\ screw axis in b direction with a pitch of the lattice parameter (figure, bottom). Interestingly, the polymeric helical chains possess two types of intrachain hydrogen bonds. One type occurs between coordinating water and uncoordinated sulfato Ο atoms with </(0-0) = 2.714 Ä and ZO-H-O = 144.8°. The other type is between the uncoordinated -NH groups of the imidazole ligands and uncoordinated sulfato Ο atoms with </(N—0) = 2.850 Ä 2.873 Ä and ZN-H-O = 173° -175°. Therefore, the polymeric helical chains are further stabilized by these relatively strong intrachain hydrogen bonds. Through the interchain N-H—Ο and O-H—O hydrogen bonds, neighboring helical chains are interlinked to form the 3D framework. On the other hand, sulfato groups exhibit slight deviation from 7d symmetry {d{S—O) = 1.450(3) Ä 1.479(3) Ä, ZO-S-O = 108.6(2)° 110.9(2)°), due to the influence of sulfato groups joining in coordination. Table 1. Data collection and handling. Crystal: Wavelength: βDifEractometer, scan mode: 20jmxi N(hkl)mt*smi, N(hkl) uaique: Criterion for /oi», N(hkl)p: N(param)nGacA·. Programs: blue rod, size 0.06 χ 0.08 χ 0.22 mm Mo Κα radiation (0.71073 Ä) 17.41 cm -1 Broker SMART CCD, φ/ω 50.18° 6897,2495 /ohe > 2 a(Idx), 1631 199 SHELXS-97 [5], S H E L X I ^ [6] * Correspondence author (e-mail: lllnl832@sina.com) 1 % CU(H20XC3H4N2)3(S04) Tabk 2. Atomic coordinates and displacement parameters (in Ä). Tabk 2. Continued. Atom Site X y ζ i/iso Atom Site X y ζ l/iso H(2A) 4e 0.5787 0.1816 0.5876 0.057 H(3) 4c 0.3881 0.5427 0.6191 0.056 H(4A) 4c 0.6556 1.1432 0.9487 0.066 H(4) 4c 0.6105 1.0158 0.8024 0.066 H(6A) 4c 0.2988 0.9545 0.5952 0.064 H(5) 4c 0.6656 0.9609 1.0800 0.066 H(5A) 4c 0.515(5) 0.493(2) 0.936(4) 0.209 H(6) 4c 0.6316 0.7097 1.0087 0.059 H(5B) 4c 0.401(4) 0.518(6) 0.934(4) 0.209 H(7) 4c 0.4904 0.8747 0.6195 0.054 H(l) 4c 0.6714 0.3345 0.7072 0.052 H(8) 4c 0.1827 0.8613 0.7236 0.070 H(2) Ae 0.4019 0.2995 0.5309 0.063 H(9) 4c 0.3129 0.7167 0.8321 0.058 Tabk 3. Atomic coordinates and displacement parameters (in Ä). Atom Site X y ζ Un i/22 i/33 Ul2 Ul3 t/23 Cu(l) 4c 0.57914(5) 0.65540(7) 0.78070(5) 0.0468(4) 0.0273(4) 0.0538(4) 0.0093(3) -0.0122(3) -0.0129(3) S(l) 4c 0.7583(1) 0.4237(1) 0.89478(9) 0.0414(7) 0.0216(6) 0.0415(7) 0.0012(5) 0.0045(6) -0.0007(5) N(l) 4c 0.5413(3) 0.4833(5) 0.6890(3) 0.036(2) 0.035(2) 0.047(2) -0.002(2) 0.000(2) -0.007(2) N(2) 4c 0.5529(4) 0.2684(5) 0.6080(3) 0.065(3) 0.027(2) 0.051(3) 0.004(2) 0.004(2) -0.014(2) N(3) 4c 0.6126(3) 0.8189(4) 0.8780(3) 0.044(2) 0.024(2) 0.051(3) 0.003(2) -0.001(2) -0.005(2) N(4) 4c 0.6452(4) 1.0452(5) 0.9431(3) 0.063(3) 0.032(3) 0.069(3) -0.012(2) 0.009(2) -0.017(3) N(5) 4c 0.4393(3) 0.7708(5) 0.7372(3) 0.046(3) 0.029(2) 0.044(3) 0.007(2) -0.002(2) -0.008(2) N(6) 4c 0.3232(4) 0.8996(6) 0.6433(3) 0.053(3) 0.053(3) 0.053(3) 0.013(2) -0.003(2) 0.007(2) 0(1) 4c 0.7216(3) 0.5462(4) 0.8261(2) 0.041(2) 0.033(2) 0.045(2) 0.006(2) -0.007(2) -0.001(2) 0(2) 4c 0.8001(3) 0.2913(4) 0.8422(2) 0.048(2) 0.026(2) 0.050(2) 0.008(2) 0.004(2) -0.007(2) 0(3) 4c 0.6625(3) 0.3760(4) 0.9543(3) 0.074(3) 0.037(2) 0.099(3) 0.007(2) 0.054(2) 0.004(2) 0(4) 4c 0.8479(3) 0.4885(4) 0.9583(2) 0.076(2) 0.031(2) 0.047(2) -0.007(2) -0.018(2) 0.003(2) 0(5) 4c 0.4598(6) 0.5072(9) 0.9009(5) 0.134(6) 0.117(6) 0.169(6) -0.029(5) 0.053(5) -0.010(5) q i ) 4c 0.6028(4) 0.3574(6) 0.6748(4) 0.043(3) 0.031(3) 0.056(3) 0.004(2) -0.005(3) -0.011(3) C(2) 4c 0.4540(5) 0.3373(6) 0.5770(4) 0.052(3) 0.046(4) 0.059(4) -0.004(3) -0.010(3) -0.019(3) C(3) 4c 0.4466(4) 0.4707(6) 0.6260(4) 0.042(3) 0.042(3) 0.056(3) 0.002(3) -0.006(3) -0.010(3) C(4) 4c 0.6208(5) 0.9693(7) 0.8626(4) 0.076(4) 0.041(4) 0.049(3) -0.002(3) 0.009(3) 0.001(3) C(5) 4c 0.6510(5) 0.9406(7) 1.0148(4) 0.068(4) 0.042(4) 0.055(3) -0.005(3) -0.008(3) -0.006(3) C(6) 4c 0.6319(4) 0.8029(6) 0.9752(4) 0.061(4) 0.034(3) 0.051(3) -0.004(3) -0.005(3) -0.001(3) C(7) 4c 0.4301(4) 0.8521(6) 0.6593(4) 0.047(3) 0.040(3) 0.048(3) -0.007(3) 0.005(2) -0.005(3) C(8) 4c 0.2604(5) 0.8462(7) 0.7158(5) 0.045(3) 0.061(4) 0.069(4) 0.014(3) 0.008(3) -0.005(3) C(9) 4c 0.3323(4) 0.7662(7) 0.7753(4) 0.053(3) 0.047(4) 0.046(3) 0.007(3) 0.013(3) -0.008(3) Acknowledgment This project was supported by the Nature Scientific Research Foundation of Shaanxi Provincial Education Office of China (grant no. 05JK155).