Synthesis and Spectral Studies of Novel Dioxomolybdenum(VI) Heterochelates Involving some Schiff Bases Derived from 4-Acetyl-3-Methyl-1-Phenyl-2-Pyrazolin-5-One

Abstract

The synthesis and physico-chemical studies of some cis-dioxomolybdenusm(VI) heterochelates with potentially bidentate and tetradentate Schiff base ligands derived from 4-acetyl-3-methyl-1-phenyl-2-pyrazolin-5-one have been described. The bidentate Schiff bases were synthesized by the reaction of 4-acetyl-3-methyl-1-phenyl-2-pyrazolin-5-one with aromatic amines, viz., o-anisidine, m-anisidine, p-anisidine, o-phenetidine, p-phenetidine, o-toluidine and m-toluidine in ethanol. For tetradentate Schiff bases, amines such as, m-phenylenediamine, p-phenylenediamine and benzidine were used. The bi- and tetradentate Schiff bases thus obtained were reacted with the parent compound, bis (acetylacetonato)dioxomolybdenum(VT), in the stoichiometric ratio (2:1 for bidentate and 1:1 for tetradentate Schiff bases) to give diamagnetic molybdenum(VI) mononuclear complexes of the compositions [MoO2(L)2 (where LH = bidentate Schiff base) and the ligand bridged binuclear complexes [{MoO2(OEt)}2(L)] (where LH2 = tetradentate Schiff base derived from benzidine or p-phenylenediamine) and [MoO2(AMPHP-MPHD)] (where AMPHP-MPHD = Schiff base of m-phenylenediamine). Suitable structures have been proposed for these complexes. Referee I: J. M. Boncella Referee II: K. Moedritzer