Synthesis and characterization of oxovanadium(IV) and dichlorovanadium (IV) complexes of biologically active 4-aminoantipyrine derivatives

Article abstract of DOI:10.1016/S0277-5387(96)00173-8

A new series of oxovanadyl complexes of the Schiff base ligands 4-(2-pyrrolyl methylideneamino)antipyrine (PyAAP), 4-(2-thienylmethylideneamino)antipyrine (TAAP), 4-furfurylideneaminoantipyrine (FAAP) and 4-(2-hydroxybenzylideneamino)antipyrine (SAAP), have been synthesized and characterized by different physical techniques. The spectral and magnetic data indicate a distorted square pyramidal structure for all complexes. The selective deoxygenation of the oxovanadyl complexes [(PyAAP-H)₂(VO)₂SO₄] and [(SAAP-H)₂VO], which gave a good yield of the corresponding dichloro compounds [L₂VCl₂], L = PyAAP-H or SAAP-H, is made by using different deoxygenating agents in different solvents and at various temperatures. The purity and the percentage yield of the products are found to be solvent, temperature and deoxygenating agent dependent. Spectral and magnetic studies are used to elucidate the structure of the dichloro derivatives. The solvent effects upon the electronic spectra of the oxovanadyl complexes and the corresponding dichloro derivatives are ascertained. Copyright