Construction of ZnII Compounds with a Chelating 2,2′‐Dipyridylamine (Hdpa) Ligand: Anion Effect and Catalytic Activities

Abstract

AbstractThe structures of new compounds containing ZnII ions and Hdpa (2,2′‐dipyridylamine)‐chelating ligands were determined. The Hdpa chelating ligands coordinate to ZnII ions to form mononuclear units (1 and 5), and intermolecular nonclassical hydrogen‐bond (C–H···O or N/C–H···I) interactions generate polymeric compounds. The chelating ligands with a bipyridyl moiety form mostly mononuclear complexes of different types (I, II and III), and the combination of this ligand with a sulfate anion can produce polymeric species (Type IV). Interestingly, homogeneous catalyst 1 catalyzed efficiently the transesterification of a variety of esters with different alcohols, and hydrogen‐bonded polymer 5 showed the heterogeneous catalytic activity for the transesterification reactions. Preliminary selectivity test of primary over secondary alcohol protection in the presence of 1 provided, exclusively, the primary acetate, which suggests the potential utility of this catalyst to be selective for primary alcohols.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)