Date Published: June 01, 2012
Publisher: International Union of Crystallography
Author(s): Xiang-Wen Wu, Qing-Long Li, Jian-Ping Ma, Yu-Bin Dong.
In the title compound, [Zn4(C16H10N4O2)4]·4H2O, the N′-[(8-oxidoquinolin-7-yl)methylidene]isonicotinohydrazidate (L2−) ligand binds to the metal ions, forming stable five- and six-membered chelate rings, leaving the pyridyl groups free. The compound is a tetranuclear ZnII complex centered about a fourfold roto-inversion axis, with the ligand coordinating in the doubly deprotonated form. The ZnII atom has a distorted square-pyramidal geometry being coordinated by one N and two O-atom donors from the doubly deprotonated L2− ligand, and by one N atom and one O-atom donor from a symmetry-related L2− ligand. In the crystal, four symmetry-related lattice water molecules, centred about a fourfold roto-inversion axis, form a cyclic tetramer through O—H⋯O hydrogen bonds. These tetramers connect to the complex molecules through O—H⋯N hydrogen bonds, forming a chain propagating along . Neighbouring molecules are linked by π–π interactions [centroid–centroid distance = 3.660 (2) Å] involving the quinolidine rings.
For heterometallic coordination polymers and coordination compounds involving bridging N-donor ligands, see: Palacios et al. (2008 ▶); Tao et al. (2002 ▶); Dong et al. (2005 ▶). For details of bond lengths in similar zinc(II) complexes, see: Kumar et al. (2006 ▶); Woodward et al. (2006 ▶).