Crystal structure and Hirshfeld surface analysis of hexa-kis-(μ-benzoato-κ2O: O')bis-(pyridine-3-carbo-nitrile-κ N1)trizinc(II)

Acta Crystallogr E Crystallogr Commun. 2017 Nov 28;73(Pt 12):1966-1970. doi: 10.1107/S2056989017016899. eCollection 2017 Dec 1.

Abstract

The asymmetric unit of the title complex, [Zn3(C7H5O2)6(C6H4N2)2], contains one half of the complex mol-ecule, i.e. one and a half ZnII cations, three benzoate (Bnz) and one pyridine-3-carbo-nitrile (Cpy) mol-ecule; the Bnz anions act as bidentate ligands through the carboxyl-ate O atoms, while the Cpy ligand acts as a monodentate N(pyridine)-bonding ligand. The complete centrosymmetric trinuclear complex thus comprises a linear array of three ZnII cations. The central ZnII cation shows an octa-hedral coordination and is bridged to each of the terminal ZnII cations by three Bnz anions. By additional coordination of the CPy ligand, the terminal ZnII cations adopt a trigonal-pyramidal coordination environment. In the crystal, the Bnz anions link to the Cpy N atoms via weak C-H⋯N hydrogen bonds, forming a two-dimensional network. C-H⋯π and π-π inter-actions [between the benzene and pyridine rings of adjacent mol-ecules with an inter-centroid distance of 3.850 (4) Å] help to consolidate a three-dimensional architecture. The Hirshfeld surface analysis confirms the role of H-atom contacts in establishing the packing.

Keywords: crystal structure; transition metal complexes of benzoic acid derivatives; zinc(II).