describes the synthesis and reactivity of platinum-based trinuclear carbonyl clusters L2PtRu2(CO)8 where L2 = 1,3-bis(diphenylphosphino)propane (dppp) and 1,2-bis(diphenylphosphino)ethane (dppe). Oxidative addition reactions of these bimetallic carbonyl clusters with methyl iodide yield products such as L2PtMeI and L2PtI2 and Ru3(CO)12. On heating with diphenylacetylene, L2PtRu2(CO)8 gives high yields of