STUDY OF THE REACTIVITY OF THE CARBON-CARBON TRIPLE BOND IN (CO)(5)M=C(OET)(C-CPH) COMPLEXES (M=CR OR W) TOWARDS [PPH(4)][HFE3(CO)(11)] OR [CO-2(CO)(8)] - A LIGAND TRANSFER-REACTION (FE) OR THERMALLY-INDUCED BUILD UP OF HETEROTRIMETALLIC CLUSTERS (CO) BRIDGED BY THE CARBYNE LIGANDS C-C(OET)=CPH-C(O)- OR C-CPH=C(OET)-C(O)-

Complexes [(CO)(5)M=C(OEt)(C=CPh)] (M = Cr (1a), W (1b)) react with [P Ph(4)][HFe3(CO)(11)] to give [PPh(4)][Fe-3(CO)(9)(mu(3)-eta(3)-C(OEt)= C=CHPh] by a ligand transfer reaction. Complexes 1a and 1b react with octacarbonyldicobalt to give [{(Co)(5)M=C(OEt)C=CPh}Co-2(CO)(6)] (M = Cr (3a) or W (3b)), 3a being characterized by an X-ray structure deter mination. In boiling hexane, 3a and 3b rearrange to the clusters 2)(CO )(7)(mu-CO)(2){mu(3)-eta(4)-CC(OEt)=CPhC(O)}] (M = Cr (4a) or W (4b)) partially characterized by an X-ray structure determination for 4a and their isomers 2)(CO)(7)(mu-CO)(2)(mu(3)-eta(4)-CCPh=C(OEt)C(O)}] (M = Cr (5a) or W (5b)) spectroscopically characterized.