The compound [Ru-3(mu(3)-ampy)(CO)(10)][BF4] (Hampy = 2-amino-6-methylpyridine), the first cationic 48-electron trinuclear carbonyl cluster bearing no hydride ligands, has been prepared in a one-pot synthesis (93% isolated yield) from [Ru-3(mu-H)(mu(3)-ampy)(CO)9], diphenylacetylene, HBF4 . OEt(2), and CO. Some substitution chemistry of [Ru-3(mu(3)-ampy)(CO)(10)][BF4] and the X-ray structure of [Ru-3(mu(3)-ampy)(CO)(9)(PPh(3))][BF4] C5H12 are also reported.