Synthesis, Crystal Structure and Spectral Properties of Copper(II) 2-Chloronicotinato Complexes with N-Heterocyclic Ligands

Abstract

The synthesis and characterization of nine new copper(II) complexes [Cu(2-Clnic)2L2] (where 2-Clnic is 2-chloronicotinate anion, L is imidazole-Im, benzimidazole-Bim, furo[3,2-c]pyridine-FP, 2-methylfuro[3,2-c]pyridine-MFP, or [1]benzofuro[3,2-c]pyridine-BFP), [Cu(2-Clnic)2(INA)] (where INA is isonicotinamide), [Cu(2-Clnic)2(4-py)]·H2O (where 4-py is 4-methylpyridine) and [Cu2(2-Clnic)4(IQ)2] (where IQ is isoquinoline) are reported. The characterizations were based on elemental analysis, infrared, electronic and EPR spectra. The dimeric character of [Cu2(2-Clnic)4(IQ)2] is assumed on the EPR spectrum and the other spectral methods. The crystal structure of the [Cu(2-Clnic)2(Bim)2] and [Cu(2-Clnic)2(FP)2] complexes have been determined by X-ray crystal structure analysis. Both complexes exhibit the hexacoordination coordination polyhedra around copper atom that lies in the crystallographic center of symmetry. The distorted tetragonal-bipyramidal (4+2) arrangement is in good agreement with spectral data that have suggested an asymmetric chelate coordination of the carboxylic group.