Supramolecular structure and substituents effect on the spectral studies of oxovanadium(IV) azodyes complexes

A series of novel bidentate azodye quinoline ligands were synthesized with various p-aromatic amines like p-(OCH3, CH3, H, Cl and NO2) in pyridine medium. All ligands have been characterized on the basis of elemental analysis, IR and 1H NMR data. The ligands obtained contain NN and phenolic functional groups in different positions with respect to the quinoline group. IR spectra show that the azo compounds (HLn) act as monobasic bidentate ligand by coordinating via the azo nitrogen atom of azodye (NN) and oxygen atom of the phenolic group thereby forming a six-membered chelating ring and concomitant formation of an intramolecular hydrogen bond. Novel vanadium azodye complexes of these ligands with general formula [OV(L1–5)2(OH2)] have been prepared by interaction of vanadyl sulfate pentahydrate with DMF solution of the appropriate ligands. The resulting complexes have been characterized on the basis of elemental analysis, molar conductance and magnetic measurements, infrared and electronic spectral studies. Suitable distorted octahedral structures have been proposed for these complexes. The Hammett’s constant is also discussed.