SYNTHESIS AND CHARACTERIZATION OF SOME DIOXOMOLYBDENUM(VI) COMPLEXES WITH O, N, S DONOR SCHIFF BASES DERIVED FROM S-METHYLDITHIOCARBAZATE, S-BENZYLDITHIOCARBAZATE, 2-AMINOETHANETHIOL, AND SUBSTITUTED SALICYLALDEHYDES

Abstract

Abstract Synthesis and characterization of some dioxomolybdenum(VI) complexes which can be represented by the general formulae MoO2(L)(EtOH) (where LH2=Schiff base derived from o-hydroxyacetophenone (hap), o-hydroxypropiophenone (hpp), and S-methyldithiocarbazate (SMDTC), S-benzyldithiocarbazate (SBDTC) and 2-aminoethanethiol (AmET)) are reported. The various Schiff base ligands prepared by condensation of appropriate amino compounds and substituted salicylaldehydes are H2hap-SBDTC (1a), H2hpp-SBDTC (2a), H2hpp-SMDTC (3a), H2hap-SMDTC (4a), H2hap-AmET (5a) and H2hpp-AmEt (6a). The various Schiff base complexes prepared by reacting cis-MoO2(acac)2 and the ligands (1a)–(6a) are MoO2(hap-SBDTC)(EtOH) (1b), MoO2(hpp-SBDTC)(EtOH) (2b) MoO2(hpp-SMDTC)(EtOH) (3b), MoO2(hap-SMDTC)(EtOH) (4b), MoO2(hap-AmET)(EtOH) (5b) and MoO2(hpp-AmET)(EtOH) (6b). These complexes have been characterized by elemental analyses, UV-Vis, IR, NMR, AAS, TGA and conductivity measurements. The complexes are monomers nonelectrolytes, diamagnetic and six-coordinated. The Schiff bases behave as dibasic tridentate ligands and coordinate through the phenolic oxygen, thioenolic sulfur and azomethine nitrogen atoms. ACKNOWLEDGMENTS One of the authors is thankful to the All India Council for Technical Education (AICTE, India) for the award of an Emeritus Professorship (KNM).