[xantsil = (9,9-dimethylxanthene-4,5-diyl)bis(dimethylsilyl)] with PCy3 led to the formation of Ru(xantsil)(CO)(PCy3) (3), in which the xantsil ligand is bound to the ruthenium center in κ3(Si,Si,O) fashion. The highly coordinatively unsaturated nature of 3 is indicated by the reaction with CO to give Ru(xantsil)(CO)3(PCy3) (5).