Syntheses and Crystal Structures of a Cadmium(Ⅱ) and a Zinc(Ⅱ) Complexes with the Flexible Ligand 1-Acetic Acid-2, 2'-biimidazole

Reactions of NaAcebiim(NaAcebiim = 1-acetic acid-2, 2′-biimidazole monosodium salt) and cadmium or zinc nitrate produce two supramolecular architectures, namely, 1D Cd(Acebiim)(NO3)(H2O)]n(1) and 0D Zn(Acebiim)2(H2O)2]·2H2O(2) in acidic aqueous solutions. Single-crystal X-ray diffraction analysis reveals that complex 1 crystallizes in the triclinic system, space group P1, and 2 is of monoclinic system, space group P21/n. In 1, two nitrate groups link two Cd(Ⅱ) ions forming Cd2(NO3)2(H2O)2] as secondary building units that are interconnected by the Acebiim- ligand into an infinite ladder. In 2, the hydrogen-bonded synthon R22(16) between the N–H moieties and carboxylic acid link Zn(Acebiim)2(H2O)2], generating a 1D-extended ribbon. Moreover, hydrogen bonds and π-π interactions further stabilize the 3D supramolecular architecture.