The triruthenium p3-alkyne complex [Ru~(CO),(~-CO)(~~-CO){~~-C~(CF~)~}(~-C~H~)~] 1 reacted with Me3N0 in MeCN to give [ R U ~( M ~C N ) ( C O ) , ( ~-C O ) ( ~~-C O ) { ~~-C , ( C F ~) ~} ( ~-C , H ~) ~] 2. This with hexafluorobut-2-yne at or below room temperature gave [ R U ~( C O ) ~( ~-C O ) { p3-q3-C3(CF3)3}(p3-CCF3)(q-C5H5)2] 3, shown by X-ray diffraction to contain a ruthenium triangle with p,-perfluoroethylidyne and p3-q 3-C3(CF3)3 ligands arising from cleavage of one of the hexafluorobut-2-yne molecules. In contrast, 2 reacted at room temperature with the alkynes diphenylethyne, methyl but-2-ynoate and but-2-yne to yield the species [Ru,(CO),(~-CO)~-(p3-C,(CF3)2R(R')}(q-C5H5)2] (R = R' = Ph; R = Me, R' = C0,Me; or R = R' = Me) respectively. X-Ray diffraction studies on the first two of these showed that the alkynes have linked to form a p3-C,(CF,),R(R') ligand bound to a closed Ru, triangle via a doubly bridging interaction with one pair of metal atoms and an q3-allyl mode with the other. Dimethyl acetylenedicarboxylate (dmad) reacted with 2 at room temperature differently again to give a structurally unidentified species [ R u ~( C O ) , { C ~( C F ~) ~} {C2(C02Me),}(q-C,H,)2], which on heating afforded [RU~(CO)~{~~-C,(CF~)~(CO,M~)~}(~-C~H,)~] 12, revealed by X-ray diffraction to contain a closo-pentagonal-bipyramidal Ru3C, cluster in which a p3-C,(CF3)2(C02Me)2 ligand bridges an open ruthenium triangle. This complex was formed directly when 1 was heated with dmad in refluxing toluene. Analogous complexes [RU,(CO)~(~~-C~(CF,)~R(R'))(~-C,H~)~] (R = Me, R' = C0,Me; R = R' = Ph; or R = R' = Me) were produced on heating 1 with methyl but-2-ynoate, diphenylethyne and but-2-yne respectively. The last two reactions also gave isomers [RU~(C~)~{~~-C,(CF~)R~(CF,))(~-C~H~)~] (R = Ph or Me) in which formal insertion of the incoming alkyne into the co-ordinated C F 3 C g C F 3 bond has occurred. In addition, the reaction of 1 with but-2-yne produced [RU~(CO)~(~-CO){~~-~~-C~(CF~)M~~]-(p3-CCF,)(q-C5H5),] analogous to 3. Diruthenium species [Ru~(CO){~-C,(CF~),R(R'))(~-C~H~)~] are formed in both toluene reflux reactions of 1 and room-temperature reactions of 2 as a result of triruthenium cluster degradation. Heating the room-temperature products [RU~(CO),(~-CO)~(~~-C~(CF~)~R~)(~-C~H,)~] confirms that these are intermediates in the formation of the complexes [ R u ~( C O ) ~( ~-C O ) { p3-q3-C3(CF3)R2)-(p3-CCF,)(q-C,H5),] and the isomeric closo clusters [ R u ~( C O ) ~{