The promoter effect of anionicnucleophiles on reactions of metal carbonyl complexes is of high current interest. 1 In par-ticular, several novel catalytic processes of potential industrial relevance are based on Ru3 (CO) 12/halide systems as catalyst precursors. 2 Besides, the association of anionic nucleophiles with Ru3 (CO) 12 in aprotic solvents gives a series of interconvertible cluster anions exhibiting enhanced activity. 1· 3 In attempts to extendearlier observations of a base-promoted catalytic CO displacement by phosphines from Ru3 (CO) 12 (l) 3a· 4 to the case of unsaturated organic ligands, we have found that the activated complex [PPN][Ru3 (m-C1)(CO) 10]([PPN][3]), which is readily obtained from the initial halide adduct [PPN][Ru3 (jj'-C1)(CO) 11]([PPN][2] 33· 11· 1)[PPN= bis (tri-phenylphosphine) iminiumj, reacts with alkynes at 25 C in THF (reaction 1) to produce a labile species [PPN][Ru3 (m-C1)(m-jj2-RCCR')(CO) 9]([PPN][4]) 5 that serves as a convenient pre-cursor to new and known6· 7 alkyne-substituted derivatives of Ru3 (CO) 12.

100% spectroscopic yield