HYDROGEN BOND INDUCED ASSEMBLY AND CRYSTAL STRUCTURES OF DIOXOVANADIUM(V) COMPLEXES WITH SCHIFF BASES

Abstract

ABSTRACT Two new dioxovanadium(V) complexes, [VO 2 L 1 ] ( 1 ) and [VO 2 L 2 ] 2 ( 2 ), where L 1 and L 2 are the deprotonated forms of 4-chloro-2-[(2-piperidin-1-ylethylimino)methyl]phenol and 2-ethoxy-6-[(2-ethylaminoethylimino)methyl]phenol, respectively, have been synthesized and characterized by i.r. spectra and single crystal X-ray diffraction. Complex ( 1 ) is a mononuclear dioxovanadium complex, with the V atom five-coordinate in a distorted square pyramidal geometry. Complex ( 2 ) is a dinuclear dioxovanadium complex, with the V atom six-coordinate in an octahedral geometry. The V∙∙∙V distance is 3.096(2) A. The hydrogen bonds among the Schiff base ligands can influence the structures of the vanadium complexes. Keywords: Synthesis; vanadium complex; Schiff base; X-ray structure analysis. INTRODUCTION A wide number of studies have focused on the Schiff bases and their metal complexes in the fields of coordination chemistry, biological chemistry, and material sciences. 1–4 In the past few decades, the vanadium complexes have been found to have interesting biological activities such as normalizing the high blood glucose levels and acting as models of haloperoxidases.