Molybdenum(VI) complex with Schiff base ligand derived from nicotionhydrazide as catalyst for the oxidation of sulfides with H2O2

Schiff bases including N, O donor atom sets are renowned to match with different metal ions and this has fascinated lots of inventors. Not only the Schiff bases perform an important role in coordination chemistry, but also, their complexes have enough potential for property of catalyst. Molybdenum biochemical role is based on its ability to facilitate electron exchanges and to form stable complexes with oxygen-, nitrogen- and sulfur-containing ligands. In combination with oxo and imido ligands, molybdenum plays a very important role in catalytic chemistry and biochemistry of molybdenum [1-2]. In this study we prepared the new complex of molybdenum with nicotinohydrazide Schiff base ligand has been prepared and fully characterized. This complex was characterized by spectroscopic methods (FT-IR, UV-Vis, 1HNMR and 13C-NMR). The prepared complex was used for oxidation of sulfides with aqueous hydrogen peroxide under reflux conditions. The reaction parameters such as catalyst amount, kind of solvent; oxidant amount and temperature were optimized in the oxidation of diphenyl sulfide (Scheme 1). The use of the complex as a catalyst for oxidation of sulfides was explored,using H2O2 as primary oxidant. First, the amount of catalyst was optimized. Next, the choice of solvent was optimized in the model reaction. Different solvents were investigated, and the highest yield of products was obtained with ethanol. In comparison with the data reported in the oxidation of organic sulfides by various Schiff base complexes, our system shows the following advantages: the cheapness, easy availability and non-toxicity of oxidant