Synthesis and X-ray Structures of Cadmium Coordination Polymers Based on New Pyridine−Carboxylate and Imidazole−Carboxylate Linkers

Three cadmium coordination polymers based on new pyridine−carboxylate and imidazole−carboxylate linkers were
synthesized hydrothermally from appropriate cadmium(II) salts and the corresponding ester or benzonitrile precursor ligands. While
cadmium bis[3-{3-(2-pyridin-4-yl-vinyl)-phenyl}-propenate] (1) adopts a three-dimensional polymeric network structure, both cadmium
bis[3-{3-(2-pyridin-4-yl-vinyl)-phenyl}-propenate] (2) and cadmium-[4-(2-imidazolylvinyl)benzoate-acetate (3) adopt two-dimensional
framework structures. In all three compounds, the carboxylate groups bridge the adjacent Cd centers to lead to centrosymmetric
coordination networks. Crystal data for 1:  monoclinic space group P21/c, a = 5.054(1), b = 8.327(2), c = 30.56(1) Å, β = 92.69(1)°, and Z = 2. Crystal data for 2:  monoclinic space group P21/c, a = 5.249(3), b = 14.977(6), c = 15.755(9) Å, β = 94.57(2)°,
and Z = 2. Crystal data for 3:  orthorhombic space group Pbca, a = 18.799(2), b = 7.754(1), c = 19.174(3) Å and Z = 8.