Synthesis and spectroscopic properties of some new seven-coordinate thioacetamide complexes of molybdenum(II) and tungsten(II)

Abstract

The compounds [MI 2(CO) 3(NCMe) 2] (M = Mo or W) react with one equivalent of SC(NH 2)Me in CH 2Cl 2 at room temperature to initially give the acetonitrile substituted products [MI 2(CO) 3(NCMe)- {SC(NH 2)Me}] which was isolated for M = W. However, the molybdenum complex rapidly dimerizes with loss of acetonitrile to give the iodide-bridged compound [Mo(σ-I)I(CO) 3 {SC(NH 2)Me}] 2. The tungsten complex does not appear to dimerize, even after stirring at room temperature for 72 h in CH 2Cl 2. Two equivalents of thioacetamide react with [MI 2- (CO) 3(NCMe) 2] in CH 2Cl 2 at room temperature to give the new bisthioacetamide compounds [MI 2- (CO) 3{SC(NH 2)Me} 2] via displacement of the labile acetonitrile ligands. The low temperature (−70 °C) 13C NMR spectrum of [WI 2(CO) 3{SC(NH 2)Me} 2] indicates that the geometry of the complex is capped octahedral with a carbonyl ligand in the unique capping position.