Bis(μ-5-carboxybenzene-1,3-dicarboxylato-κ2O1:O3)bis[(2,2'-bi-1H-imidazole-κ2N3,N3')zinc]

Acta Crystallogr C. 2011 Sep;67(Pt 9):m297-300. doi: 10.1107/S0108270111031349. Epub 2011 Aug 11.

Abstract

The title compound, [Zn(2)(C(9)H(4)O(6))(2)(C(6)H(6)N(4))(2)], consists of two Zn(II) ions, two 5-carboxybenzene-1,3-dicarboxylate (Hbtc(2-)) dianions and two 2,2'-bi-1H-imidazole (bimz) molecules. The Zn(II) centre is coordinated by two carboxylate O atoms from two Hbtc(2-) ligands and by two imidazole N atoms of a bimz ligand, in a distorted tetrahedral coordination geometry. Two neighbouring Zn(II) ions are bridged by a pair of Hbtc(2-) ligands, forming a discrete binuclear [Zn(2)(Hbtc)(2)(bimz)(2)] structure lying across an inversion centre. Hydrogen bonds between carboxyl H atoms and carboxylate O atoms and between imidazole H atoms and carboxylate O atoms link the binuclear units. These binuclear units are further extended into a three-dimensional supramolecular structure through extensive O-H···O and N-H···O hydrogen bonds. Moreover, the three-dimensional nature of the crystal packing is reinforced by the π-π stacking. The title compound exhibits photoluminescence in the solid state, with an emission maximum at 415 nm.