Multiple oxidative addition of diphenyl-2-thienylphosphine selenide to [Ru3(CO)12]: crystal and molecular structure of [Ru3(μ3-Se)(μ-PPh2)(μ-η1:η2-C4H3S)(CO)6{P(C4H3S)Ph2}]

The reaction of Ph2(C4H3S)PSe with [Ru3(CO)12] affords the open triangular 50-electron cluster [Ru3(μ3-Se)2(CO)7{P(C4H3S)Ph2}2] (1) and the 48-electron cluster [Ru3(μ3-Se)(μ-PPh2)(μ-C4H3S)(CO)6{P(C4H3S)Ph2}] (2) derived by the multiple fragmentation of one phosphine ligand on the metal triangle. The same cluster core is also exhibited by a major ionic fragment detected in the mass spectrum of 1, suggesting that 2 is a secondary product derived from decomposition of 1. The molecular structure of 2, determined by X-ray diffraction methods, shows two (a phosphide and a thienyl) ligands bridging two sides of the metal triangle, which is capped by the selenium atom ligand. The bridging (μ-η1:η2) thienyl moiety approaches a side of the metal triangle with the σ-bound carbon nearly coplanar with the ruthenium atoms.