Synthesis and spectroscopic properties of the novel cationic alkyne complexes [WI(CO)(NCMe)L 2(η 2-RC 2R)][BF 4] (L = PEt 3 or PMe 2Ph; R = Me or Ph)

Abstract

The complexes [WI 2(CO)L 2(η 2-RC 2R)] (L = PEt 3 or PMe 2Ph; R = Me or Ph) react with an equimolar quantity of Ag[BF 4] in acetonitrile at room temperature to give good yields of the new purple cationic alkyne complexes [WI(CO)(NCMe)L 2(η 2-RC 2R)][BF 4]. 31P NMR spectroscopy indicates that the phosphines are trans to each other in these compounds. 13C NMR spectroscopy suggests that the alkyne ligands are donating four electrons to the tungsten in these complexes.