High-nuclearity ruthenium carbonyl cluster chemistry. 8: Phosphine activation, CO insertion, and deruthenation at a phosphido cluster – X-ray structures of [ppn][Ru8(μ8-P)(μ-CO)2(CO)20] and [ppn][Ru7(μ7-P)(μ-η2-OCPh)(μ-PPh2)(μ-CO)(CO)17]

Reaction of the square antiprismatic cluster [ppn][Ru8(μ8-P)(μ-CO)2(CO)20] [ppn = bis(triphenylphosphoranylidene)ammonium] with triphenylphosphine proceeds by loss of one cluster core vertex, phosphine P–C cleavage, and CO insertion into the putative Ru–phenyl bond to afford [ppn][Ru7(μ7-P)(μ-η2-OCPh)(μ-PPh2)(μ-CO)(CO)17] in low yield, the first heptaruthenium μ7-phosphido-ligated cluster.