Anion effect on construction of two Cd(II) coordination polymers with phenylformic acid-imidazole ditopic ligand: Hydrothermal synthesis, crystal structure and antimicrobial activity

Two new coordination polymers, [Cd(L−H)2] ∞ (1) and [Cd(L−H)(NO3)] ∞ (2) (L = C10H8N2O2), have been synthesized by hydrothermal reactions of 4-(imidazole-1-yl)-benzoic acid and CdX2 (X = and ). X-ray single crystal diffraction demonstrates that the counterion has an important effect on the assembly process. Crystals of 1 were orthorhombic, space group Pnna, with a = 13.8052(6), b = 16.5126(10) and c = 8.2158(12). Complex 2 crystals were isolated as orthorhombic, space group Pbca, with a = 7.9988(6), b = 15.8290(11) and c = 17.9580(13). Cd2+ is six-coordinate in a distorted octahedral geometry in both complexes. In 1, L bridges the metal centers with the intramolecular Cd ··· Cd separation of 11.651 Å, resulting in an infinite rhombic grid; is not in the grid. In 2, adjacent Cd(II)'s were linked by L, and further by nitrate and carboxylate, producing an infinite zigzag chain. The toxicity of the two complexes is evaluated by testing antimicrobial activity against bacterial strands using the agar diffusion method.