Anion effects on the crystal structures of ZnII complexes containing 2,2′-bipyridine: Their photoluminescence and catalytic activities

Six new structures of Zn-II complexes containing 2,2'-bipyridine (2,2'-bpy) ligands have been determined. Halide anions were used as simple coordinating ligands to form a tetrahedral environment around the Zn-II ion. Nitrate and benzoate anions were used as chelating ligands to form an octahedral environment. For non-coordinating ClO4- and bridging SO42- anions, three 2,2'-bpy ligands chelate Zn-II to form an octahedral environment, and both ClO4- and SO42- anions occupy empty positions between the metal cations for charge balance. Polymeric structures of the Zn-II-2,2'-bpy complexes are produced by hydrogen bonding. [Zn(2,2'-bpy)(O2CC6H5)(2)] catalyzed efficiently the transesterification reaction of esters with methanol under the neutral conditions, while the remaining compounds showed very slow conversions. (C) 2011 Elsevier Ltd. All rights reserved.