Preferential hexacoordination of cobalt(II) complexes with heteroaroyl-hydrazones

Abstract

<span style="font-size:14.0pt;font-family:" times="" new="" roman";="" mso-fareast-font-family:"times="" roman";mso-ansi-language:en-us;mso-fareast-language:="" en-us;mso-bidi-language:ar-sa"="">Cobalt(II) &nbsp;complexes of benzoic acid [(furan-2-yl) methyl enejhydrazide, benzoic acid [1-(furan-2-yl ) ethylidenel] hydrazide, benzoic acid {(thiophen-2-yl)methylene hydrazide and benzoic acid [1-(thiophen-2-yl)-ethylidene] hydrazide have been synthesized and characterized by elemental analysis, conductivity, magnetic susceptibility measurements, <b style="mso-bidi-font-weight: normal">IR</b> and electronic spectral data. Various ligand field parameters have been calculated. Electronic spectral data and the magnetic moment values suggest an octahedral structure for all cobalt(II) complexes. This observation suggests ligand independent structural features of cobalt complexes of aroylhydrazones. The cyclic voltammetric results suggest that BFEH has greater ability to stabilize cobalt(II) oxidation state.</span>