Microwave Synthesis, Reactivity, Electrical and Spectral studies of Oxovanadium (iv) Complexes Schiff base ligands derived from Diphenylglyoxal Moiety

Microwave-assisted synthesis has emerged as a powerful technique in modern chemistry, offering a sustainable and efficient alternative to conventional thermal methods. Microwave irradiated reactions under solvent free or less solvent conditions are attractive offering shorter reaction times, improved yields, and cleaner products with simplicity in processing and handling. Vanadium containing compounds have their utility in various physico-chemicals, biochemical physiological, enzymatic and catalytic processes. Novel solid complexes of oxovanadium(IV) with the Schiff bases viz. diphenylglyoxalidene - α, α-bis (2-aminophenol) (DAPh), diphenylglyoxalidene-α,α-bis (2-amino-4-chlorophenol) (DACp), diphenylglyoxalidene-α, α’-bis (2-aminopyridine) (DAPy) and diphenylglyoxalidene - α, α’-4-chloro-1,3-phenylenediamine (DCPa) have been synthesized by conventional as well as microwave methods. These compounds have been characterized by elemental analyses, thermal data, FAB mass, FT-IR, molar conductance, electronic spectra, ESR and magnetic measurements. FAB mass and thermal data give information about degradation pattern of complexes. The Schiff base ligands DAPh, DACp, DAPy and DCPa behave as tetradentate and bidentate coordinating through N2O2/ N4 and N2 donor, respectively. Molar conductance (10-3 M in MeOH) values show that VO-DAPh/DACp complexes are non-electrolytes and VO-DAPy/DCPa complexes have 2:2 electrolytic in nature. The proposed geometry of oxovanadium (IV)- Schiff base complexes are square pyramidal. The reactivity and substitution behaviour of the synthesized complexes have also been studied. Solid state AC-electrical conductivity studies reflect semiconducting nature of the complexes.