88801-71-2Relevant academic research and scientific papers
Alkyne scission on a trimetallic framework: Experimental evidence and theoretical analysis
Clauss, Allen D.,Shapley, John R.,Wilker, Charles N.,Hoffmann, Roald
, p. 619 - 623 (1984)
The conversion of an alkyne complex, Cp3M3(CO)(C2R2), into a dialkylidyne complex, Cp3M3(CR)2, has been examined theoretically (M = Co; R = H) and experimentally (M = Rh, Ir; C2R2 = C2Ph2, C2PhTol). The alkyne complexes have been synthesized in useful amounts via photolysis of Cp3M3(CO)3 in the presence of excess alkyne. Flash vacuum pyrolysis of the alkyne complexes cleanly provides the corresponding dialkylidyne complexes. The reaction proceeds without fragmentation of the trimetallic framework and without exchange of the CR moieties. No evidence was obtained for an unsaturated alkyne complex Cp3M3(C2R2) as an intermediate. The theoretical analysis shows that such an intermediate leads to a much higher energy pathway for alkyne scission than a pathway in which the carbonyl ligand remains coordinated until the alkyne is cleaved.
