Two ZnII mononuclear coordination compounds with pyridinedicarboxylate and auxiliary N-(pyridin-4-ylmethylidene)hydroxylamine ligands

Two new mononuclear coordination compounds, bis{4-[(hydroxyimino) methyl]pyridinium} diaquabis(pyridine-2,5-dicarboxylato-kappa N-2,O-2) zincate(II), (C6H7N2O)(2)[Zn(C7H3NO4)(2)-(H2O)(2)], (1), and (pyridine-2,6-dicarboxylato-k(3)O(2),N,O-6)bis[N-(pyridin-4-ylmethylidene-kappa N) hydroxylamine]zinc(II), [Zn(C7H3NO4)(C6H6N2O)(2)], (2), have been synthesized and characterized by single-crystal X-ray diffractometry. The centrosymmetric Zn-II cation in (1) is octahedrally coordinated by two chelating pyridine-2,5-dicarboxylate ligands and by two water molecules in a distorted octahedral geometry. In (2), the Zn II cation is coordinated by a tridentate pyridine-2,6-dicarboxylate dianion and by two N-(pyridin-4-ylmethylidene)hydroxylamine molecules in a distorted C-2-symmetric trigonal bipyramidal coordination geometry.