Reactions of [WI2(CO)(NCMe)(η2-RC2R)2] (R = Me or Ph) with 1,4-diaza-1,3-butadienes

Article abstract of DOI:10.1016/S0277-5387(00)81183-3

Reaction of [WI₂(CO)(NCMe)(η²-RC₂R)₂] (R = Me or Ph) in CH₂Cl₂ at room temperature with an equimolar quantity of R′N: CHCH: NR′ (R′ = Cy, ⁱPr, Ph, p-MePh or p-MeOPh) gave high yields of the new cationic bisalkyne complexes [WI(CO)(R′N: CHCH: NR′)(η²-RC₂R)₂]I via successive displacement of acetonitrile and an iodide ligand. The cationic compounds [WI(CO)(CyN: CHCH: NCy)(η²-RC₂R)₂][BPh₄] were also prepared by reaction of [WI₂(CO)(NCMe)(η²-RC₂R)₂] with CyN: CHCH: NCy in the presence of Na[BPh₄] in order to confirm the ionic nature of these complexes. ¹³C NMR spectroscopy indicated that the two alkyne ligands are donating a total of six electrons to the metal in these complexes.