Mixed ligand oxovanadium(IV) complexes with salicylic acid and N,N-bidentate ligands

Abstract

<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" calibri;mso-fareast-theme-font:minor-latin;mso-hansi-theme-font:minor-latin;="" mso-bidi-font-family:"times="" new="" roman";mso-bidi-theme-font:minor-bidi;="" mso-ansi-language:en-in;mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">Two mixed-ligand oxovanadium(IV) complexes VO(A)(B) [where H₂A=salicylic acid and B=2,2'-bipyridine or 1,10- phenanthroline (hereafter, bipy and phen respectively)] have been synthesized and characterized by magnetic moment and spectral (IR, UV/VIS and EPR) data. The A^2- ion acts as a bidentate dinegative ligand while B ligands act as a neutral bidentate. The magnetic susceptibility values indicate the existence of a small amount of anti ferromagnetic interaction. The vanadium atoms in the complexes are hexacoordinated and the coordination sphere is of the type [VO(OO)(NN)], where O atoms are of oxo, carboxylic and phenolic type and N atoms are of pyridine type. The sixth coordination site is occupied by phenolic oxygen of the neighbouring molccule forming a bridge. The v_v=o confirms the hexacoordination. All the complexes have d_xy¹ type axial EPR spectra and they exhibit two ligand field transitions at 740 and 440 nm.</span>