SYNTHESIS AND CHARACTERIZATION OF CIS-DIOXOMOLYBDENUM(VI) SCHIFF-BASECOMPLEXES DERIVED FROM 1-PHENYL-3-METHYL-4-BENZOYL-5-PYRAZOLONE

The synthesis and characterization of some cis-dioxomolybdenum(VI) com plexes with bidentate and tetradentate Schiff base ligands derived fro m reactions of 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone with amines, s uch as p-anisidine, m-phenitidine, m-toluidine, o-, m- and p-phenylene diamine, and benzidine are reported. Reaction of the bi- and tetradent ate Schiff bases with MoO2(acaC) 2 in 2:1 and 1:1 ratios, respectively , gave diamagnetic molybdenum(VI) mononuclear complexes with the gener al formulae cis-MoO2(L)2 (L = bidentate Schiff base), CiS-MoO2(L1) (L1 = tetradentate Schiff base with o- and m-phenylenediamine) and the li gand-bridged dinuclear complexes Mo2O4(L2)(S) (L 2 =tetradentate Schif f base with p-phenylenediamine and benzidene, S = C2H5O- and x = 2 or 4). These complexes were characterized by elemental analysis, molar co nductance, IR, UV-vis, H-1 NMR and cyclic voltammetry.