Ruthenium cluster chemistry: Monodentate bis(diphenylphosphino)acetylene-ligated cluster modules in chain and dendrimer formation

Reaction of Ru3(CO)9(NCMe)3 with excess Ru3(μ-dppm)(CO)9(η1-dppa),which possesses a monodentate dppa ligand,or reaction of excess Ru3(μ-dppm)(CO)10 with Ru3(CO)9(η1-dppa)3,which possesses three monodentate dppa ligands,affords the dodecanuclear first-generation dendrimer Ru3(CO)9{PPh2C2PPh2Ru3(μ-dppm)(CO)9}3.Reaction of WIr3(μ-CO)3(CO)8(η-C5Me5) with excess Ru3(μ-dppm)(CO)9(η1-dppa) affords the decanuclear tri-cluster WIr3(CO)9{PPh2C2PPh2Ru3(μ-dppm)(CO)9}2(η-C5Me5).