Synthesis and characterization of oxovanadium(IV) complexes incorporating novel tridentate OOO donor ligands

Abstract

Department of Chemistry, Ramakrishna Mission Vidyamandira, Belur Math, Howrah-711 202, West Bengal, India Post Graduate Department of Chemistry, Ramakrishna Mission Vivekananda Centenary College, Rahara, Kolkata-700 118, India Manuscript received 24 April 2013, accepted 03 July 2013 VOSO₄ reacts with equivalent amount of 1-(2-hydroxyphenyl)butane-1,3-dione (H₂L¹ ) and 1-(2-hydroxyphenyl)- 3-phenyl-propane-1,3-dione (H₂L² ) in presence of two equivalent sodium acetate in 50% (v/v) aqueous-methanolic medium to afford the brown complexes [V^IVO(L¹ )(H₂O)]n (1) and [V^IVO(L² )(H₂O)]n (2) respectively. IR spectra and solubility of complexes in common organic solvent along with the geometry of the ligands indicated the polymeric nature of the complexes. Complexes are one-electron paramagnetic and are EPR active displaying axial EPR spectra in DMSO solution at 77 K. They exhibit three transitions in the visible region at ~660 nm, ~590 nm and ~430 nm due to d_xy → d_xz, d_yz; d_xy → d_x² –_y² and d_xy → d_z² respectively.