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)]center dot 2H(2)O (2) in acidic aqueous solutions. Single-crystal X-ray diffraction analysis reveals that complex 1 crystallizes in the triclinic system, space group P (1) over bar, and 2 is of monoclinic system, space group P2(1)/n. In 1, two nitrate groups link two Cd(II) ions forming [Cd-2(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 R-2(2)(16) between the N-H moieties and carboxylic acid link [Zn(Acebiim)(2)(H2O)(2)], generating a 1D-extended ribbon. Moreover, hydrogen bonds and pi-pi interactions further stabilize the 3D supramolecular architecture.