Nickel and zinc complexes with a monodentate heterocycle and tridentate Schiff base ligands: self-assembly to one- and two-dimensional supramolecular networks via hydrogen bonding.

In the complex (morpholine)[2-hydroxy-N'-(5-nitro-2-oxidobenzylidene)benzohydrazidato]nickel(II), [Ni(C(14)H(9)N(3)O(5))(C(4)H(9)NO)], (I), the Ni(II) center is in a square-planar N(2)O(2) coordination geometry. The complex bis[mu-2-hydroxy-N'-(2-oxidobenzylidene)benzohydrazidato]bis[(morpholine)zinc(II)], [Zn(2)(C(14)H(10)N(2)O(3))(2)(C(4)H(9)NO)(2)], (II), consists of a neutral centrosymmetric dimer with a coplanar Zn(2)(mu(2)-O)(2) core. The two Zn(II) centers are bridged by phenolate O atoms. Each Zn(II) center exhibits a distorted square-pyramidal stereochemistry, in which the four in-plane donors come from the O,N,O'-tridentate 2-hydroxy-N'-(2-oxidobenzylidene)benzohydrazidate(2-) ligand and a symmetry-related phenolate O atom, and the axial position is coordinated to the N atom from the morpholine molecule. There are intramolecular phenol-hydrazide O-H...N hydrogen bonds present in both (I) and (II). In (I), square-planar nickel complexes are linked by intermolecular morpholine-morpholine N-H...O hydrogen bonds, leading to a one-dimensional chain, while in (II) an infinite two-dimensional network is formed via intermolecular hydrogen bonds between the coordinated morpholine NH groups and the uncoordinated phenolate O atoms.