Synthesis, Characterization, and Crystal Structures of New Oxovanadium(V) Complexes With Mixed Nicotinohydrazone and 8-Hydroxyquinoline Ligands

Two similar oxovanadium(V) complexes, [(VOLL)-L-1 '] (1) and [(VOLL)-L-2 '] (2), were prepared by the reaction of [VO(acac)(2)] (where acac = acetylacetonate), 8-hydroxyquinoline (HL ') with N '-(5-fluoro-2-hydroxybenzylidene)nicotinohydrazide (H2L1) and N '-(3-bromo-5-chloro-2-hydroxybenzylidene)nicotinohyrazide (H2L2), respectively, in methanol. Crystal and molecular structures of the complexes were determined by elemental analysis, infrared, and UV-vis spectra and single-crystal X-ray diffraction. The nicotinohydrazone ligands coordinate to the V atoms through the phenolate oxygen, imino nitrogen, and enolate oxygen. The 8-hydroxyquinoline ligand coordinates to the V atom through the phenolate oxygen and pyridine nitrogen. The V atoms in both complexes are in octahedral coordination.