Reactivity of the 1-azavinylidene cluster [Ru3(μ-H)(μ-N=CPh2)(CO)10] with hydrogen, tertiary silanes and tertiary stannanes

The reactivity of the 1-azavinylidene cluster [Ru-3(mu-H)(mu-N=CPh2)(CO)(10)] (1) with hydrogen, tertiary silanes and tertiary stannanes has been investigated. The reaction of 1 with hydrogen (1 atm, 110 degrees C) gives [Ru-4(mu-H)(4)(CO)(12)] and H2NCHPh2 as end-products, proceeding via the imido and amido intermediates [Ru-3(mu-H)(2)(mu(3)-NCHPh2)(CO)(9)] (2) and [Ru-3(mu-H)(mu-HNCHPh2)(CO)(10)] (3), respectively. Although no reaction is observed between compound 1 and tertiary organosilanes at 110 degrees C, 1 reacts readily with tertiary organostannanes to give [Ru-3(mu-H)(2)(mu-N=CPh2)(SnR3)(CO)(9)] (4: R = Ph; 5: R = Bu). H-1-NMR spectroscopy and the X-ray structure of the triphenylstannyl derivative 4 demonstrate that the addition of the stannane reagents to 1 takes place on the cluster metal framework. No transfer of the stannyl group from the metal to the azavinylidene ligand is observed at 110 degrees C. This is in contrast with the results obtained in the hydrogenation of 1, where reduction of the azavinylidene ligand is observed under comparable reaction conditions. (C) 1998 Elsevier Science S.A. All rights reserved.