Molybdenum(VI), uranium(VI) and vanadium(V) complexes of 4-acylbis(1-phenyl-3-methylpyrazolone-5): Synthesis and spectroscopic characterization

The synthesis and characterization of metal complexes of 4-adipoyl and 4-se bacoyl derivatives of bis(1-phenyl-3-methylpyrazolone-5) with Mo(VI), U(VI) and V(V) are reported. Analytical and spectroscopic data show that the com plexes are neutral and conform to a general empirical formula MO2(L)(a)(HL) (b). xH(2)O where M is the metal; L is 4-acylbis(1-phenyl-3-methyl-pyrazolo ne-5) dianion; a = 0 or 1; b = 0 or 1 and x = 0, 1/2 or 1. The molybdenum c omplex of the 4-adipoyl derivative was, however, found to conform to an emp irical formula of (MO2)(2)(L)(OH)(OCH2CH3) suggesting that two moles of Mo( VI) interacted with one mole of the ligand to form a neutral complex. IR sp ectral analysis showed that O=V=O and O=Mo=O species existed as the cis-for m in the V(V) and Mo(VI) complexes respectively. The UV-visible, IR and NMR spectral data of the complexes were reported.