Synthesis, spectral properties, and crystal structure of {methoxo[4-phenylbutane-2,4-dione(p-nitrobenzoyl) hydrazonato(2-)]oxovanadium(V)}

The hydrazino complex {methoxo[4-phenylbutane-2,3-dione(p-nitrobenzoyl)hydr azonato(2-)]oxo-vanadium(V)}, VO(p-NO(2)bhbzac)OCH3, (1), has been prepared by the direct reaction of bis(benzoylacetonato) oxovanadium(IV), VO(bza)(2 ), with p-NO2-C6H4C(O)NHNH2, p-NO(2)bh, in CH3OH. The resulting compound co ntains benzoylacetone-(p-NO2)benzoyl hydrazone as tridentate Schiff base-ty pe ligand and OCH3 group as Lewis base, both ligated to vanadium. The cryst als are orthorhombic, with Z = 8, space group Pbca, a = 11.699(5) Angstrom, b = 14.035(5) Angstrom, c = 22.564(5) Angstrom, R1 = 0.0756 and wR2 = 0.13 02. The crystal structure demonstrated the square-pyramidal geometry of the VOoxo(ONO)O coordination sphere with the oxo ligand at the apical position . The electronic absorption spectra revealed a ligand-tu-metal charge-trans fer (LMCT) band in the near UV region at lambda (max) = 23,700 cm(-1) (B = 5640 dm(3) mol(-1) cm(-1)) in CH3CN, lambda (max) = 23,420 cm(-1) (B = 5550 dm(3) mol(-1) cm(-1)) in DMSO, and lambda (max) near 26,950 (sh) cm(-1) (B = 10,550 dm(3) mol(-1) cm(-1)) in CH2Cl2. The FT-IR spectra of (1) show th e characteristic strong nu (V = O) stretching vibration at 993 cm(-1) and s upport the view that the oxovanadium complex is pentacoordinated and monome ric.