SOME ASPECTS OF THE CHEMISTRY OF SILYLIDENE-PHOSPHANES AND SILYLIDENE-ARSANES

This paper summarizes some advances in the chemistry of silanylidene-p hosphanes (''phosphasilenes'', Si=P) and silanylidene-arsanes (''arsas ilenes'', Si=As) which have been achieved since 1991. The easy access to stable phospha- and arsa-silenes, having silyl groups attached to t he low-coordinate pnictogen atoms, has allowed the study of the molecu lar structures, NMR spectroscopic properties, and reactivity. It turne d out that the structural and chemical features for phospha- and arsa- silenes are distinctly different to those observed for iminosilanes (S i=N).