The cluster complex Ru-5(CO)(12)(C6H6)(mu(5)-C), 1, undergoes multiple addition reactions with Ph3SnH to yield two new bimetallic cluster complexes: Ru-5(CO)(8)(mu-SnPh2)(4)(C6H6)(mu(5)-C), 2, 2% yield, and Ru-5 (CO)(7)(mu-SnPh2)(4)(SnPh3)(C6H6)(mu(5)-C)(mu-H), 3, 26% yield, containing four and five tin ligands, respectively. Both compounds consist of a square pyramidal Ru-5 cluster with an interstitial carbido ligand and bridging SnPh2 groups located across each of the four edges of the base of the Ru-5 square pyramid. Compound 3 contains an additional SnPh3 group terminally coordinated to one of the ruthenium atoms in the square base.