Triphenylbismuth seven-coordinate complexes of molybdenum(II) and tungsten(II)

Abstract

The seven-coordinate complexes [MI 2(CO) 3(NCMe) 2] (M = Mo and W) react with one equivalent of BiPh 3 in CH 2Cl 2 at room temperature to give the monoacetonitrile complexes [MI 2(CO) 3(NCMe)(BiPh 3)]. The molybdenum complex [MoI 2(CO) 3(NCMe)(BiPh 3)] after stirring in CH 2Cl 2 at room temperature for 5 h affords the iodide-bridged dimer [Mo(μ-I)I(CO) 3(BiPh 3)] 2, whereas the tungsten complex [WI 2(CO) 3(NCMe)(BiPh 3)] does not appear to dimerise even after stirring for 48 h in CH 2Cl 2 at room temperature. Reaction of [MI 2(CO) 3(NCMe) 2] with two equivalents of BiPh 3 gives the bistriphenylbismuth compounds [MI 2(CO) 3(BiPh 3) 2] in good yield. The new mixed ligand complexes [MI 2(CO) 3L(BiPh 3)] were prepared either by reaction of [MI 2(CO) 3(NCMe)(BiPh 3)] in situ with one equivalent of L(L = P(OPh) 3), or an in situ reaction of [MI 2(CO) 3(NCMe)L] (L = PPh 3 and SbPh 3; and L = AsPh 3 and PPh 2Cy (for M = Mo only) with an equimolar quantity of BiPh 3. Reaction of [MoI 2(CO) 3(NCMe)(BiPh 3)] with one equivalent of 2,2′-bipyridyl (bipy) in CH 2Cl 2 at room temperature afforded the cationic complexes [MoI(CO) 3(bipy)(BiPh 3)]I in good yield. The complex [WI 2(CO) 3(NCMe)(BiPh 3)] (prepared in situ) reacts with two equivalents of NaS 2CNMe 2·2H 2O to eventually give the non-triphenylbismuth containing product [W(CO) 3(S 2CNMe 2) 2] in high yield.