Synthesis and antifungal activity of oxovanadium(IV) complexes with Schiff bases

A series of preparations are reported representing complexes between a range of ligands KHL = potassium salt of salicylidene-β-alanine, A¹ = 2,2′-bipyridylamine, A² = bis(benzylidene)ethylenediamine, A³ = thiophene-o-carboxaldene-aniline, A⁴ = thiophene-o-carboxaldene-p-toluidine, A⁵ = bis(benzylidene)-1,8-diaminonaphthalene, A⁶ = bis(acetophenone)ethylenediamine] and oxovanadium(IV) ion. Relevant electronic (UV), infrared (IR) spectra, thermogravimetric analyses, elemental analyses, and magnetic measurements are reported and interpreted in terms of the metal ion coordination geometry and, where appropriate, the likely octahedral structures of the compounds. The complexes are paramagnetic in nature. The antifungal activity of the complexes against A. niger, F. oxysporum, and A. flavus species is reported. All the tested complexes show higher antifungal activity as compared to free ligands, vanadyl sulfate, and the control (DMSO), but moderate activity as compared to the reference fungicides bavistin and emcarb. Published in Khimiko-Farmatsevticheskii Zhurnal, Vol. 40, No. 9, pp. 32–35, September, 2006.