Synthesis, spectral and EPR studies of oxovanadium(IV) complexes incorporating tridentate ONO donor hydrazone ligands: Structural study of one oxovanadium(V) complex

Five oxovanadium(IV) complexes of 2-hydroxy-4-methoxybenzaldehyde nicotinic acid hydrazone (H2L1), 2-hydroxy-4-methoxyacetophenone nicotinic acid hydrazone (H2L2) and a binuclear oxovanadium(V) complex of H2L2 have been synthesized. These complexes were characterized by different physicochemical techniques like electronic, infrared and EPR spectral studies. The complexes [VOL1]2 · H2O (1) and [VOL2]2 · H2O (4) are binuclear and [VOL1bipy] (2), [VOL1phen] · 1.5H2O (3) and [VOL2phen] · 2H2O (6) are heterocyclic base adducts and are EPR active. In frozen DMF at 77 K, all the oxovanadium(IV) complexes show axial anisotropy with two sets of eight line patterns. The complex [VOL2 · OCH3]2 (5) is an unusual product and has distorted octahedral geometry, as obtained by X-ray diffraction studies.

Five oxovanadium(IV) complexes of 2-hydroxy-4-methoxybenzaldehyde nicotinic acid hydrazone (H2L1), 2-hydroxy-4-methoxyacetophenone nicotinic acid hydrazone (H2L2) and a binuclear oxovanadium(V) complex of H2L2 have been synthesized. These complexes are characterized by different physicochemical techniques like electronic, infrared and EPR spectral studies. The complexes [VOL1]2 · H2O (1) and [VOL2]2 · H2O (4) are binuclear and [VOL1bipy] (2), [VOL1phen] · 1.5H2O (3) and [VOL2phen] · 2H2O (6) are heterocyclic base adduct complexes and are EPR active. In frozen DMF at 77 K, all the oxovanadium(IV) complexes show axial anisotropy with two sets of eight line pattern. The complex [VOL2 · OCH3]2 (5) is an unusual product and having distorted octahedral geometry, as obtained by X-ray diffraction studies.Figure optionsDownload as PowerPoint slide