A New Side-on End-On Ditantalum Dinitrogen Complex and Its Reaction with BuSiH3

The formation of the P-cyclohexyl dinitrogen complex, (CyPh[NPN]Ta)(2)(mu-eta(2):eta(1)-N-2)(mu-H)(2) ((CyPh)[NPN] = [CyP(CH2SiMe2NPh)(2)], and Cy = C6H11) is described and its reaction with butylsilane (BuSiH3) explored. The reaction was monitored by multinuclear NMR spectroscopy and showed the formation of a number of intermediates. The final product is a hydride-bridged imidoamido silyated species that has the imido bridging between the two central tantalum atoms. The origin of the bridging hydrides in the product is likely to arise from the excess silane present, on the basis of labeling studies.