Non-covalent interaction in metal cation-directed assembly of supramolecular architectures: Synthesis, characterization and crystal structures

Three new complexes [Zn(NCS)(2)L-2] (1), [Hg(SCN)(2)L-2] (2) and [Mn(NCS)(2)L-4] (3), have been synthesized by the self-assembly of 4-imidazolychalcone (abbreviated as L) with M(SCN)(2) (M = Hg2+, Zn2+, Mn2+). The complexes have been characterized by spectroscopic and crystallographic methods. H-1 NMR spectra of complexes 1-3 present that metal ions have effect on the chemical shifts of protons of coordinated groups. Three complexes illustrate different molecular structures due to the different coordinated modes of the metal ions. In the title complexes, the coordination geometries of Zn, Hg and Mn ions are tetrahedral N-4, N2S2 and octahedral N-6, respectively. Finally, hydrogen bonding interactions assemble the different coordination units into higher-dimensional frameworks. The results show that the metal ion and weak non-covalent interactions play important roles in the construction of the final supramolecular structures. (c) 2012 Published by Elsevier Ltd.