Four-, five- and six-coordinated complexes of ZnII with OHrich molecules possessing an ONO binding core were synthesized, characterized and their structures were established by single-crystal X-ray diffraction. The corresponding metal ion geometries were found to be distorted tetrahedral, square pyramidal and octahedral, respectively. The complexes exhibit interesting lattice structures such as layered and corrugated sheets owing to the presence of a number of weak intermolecular interactions. The five-coordinated, water-bound ZnII complex was studied because of its putative hydrolysis property towards p-nitrophenyl acetate. © Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.