The Preparation of Some Monodentate Coordinated Semicarbazone(O) and Thiosemicarbazone(S) Cationic But-2-yne Tungsten(II) Complexes

Abstract

Reaction of [WI(CO)(NCMe)(dppm)(η2-MeC2Me)][BF4] {dppm = Ph2P(CH2)PPh2} with an equimolar quantity of L {L = RR′CNNHCONH2 (R = R′ = Me; R = H, R′ = Ph)} or L {L = RR′CNNHCSNH2 (R = R′ = Me, Et; R = Me, R′ = Et, Prn, But, Ph; R = H, R′ = Ph)} gives the monodentately coordinated semicarbazone or thiosemicarbazone products [WI(CO)L(dppm)(η2-MeC2Me)][BF4] (1-9). 13C NMR spectroscopy suggests that the but-2-yne ligand is donating four electrons to the tungsten in [WI(CO){H(Ph)CNNHCSNH2}(dppm)(η2-MeC2Me)] [BF4].