37048-23-0Relevant academic research and scientific papers
Reactions of transition-metal-propargyl compounds with dicobalt octacarbonyl. New heterobinuclear μ-alkyne complexes
Wido, Thomas M.,Young, George H.,Wojcicki, Andrew,Calligaris, Mario,Nardin, Giorgio
, p. 452 - 458 (2008/10/08)
Reactions of transition-metal-propargyl complexes [M]CH2C≡CR with Co2(CO)8 in pentane at room temperature afford the trinuclear products (CO)3Co(μ-RC2CH2[M]Co(CO)3 ([M] = CpFe(CO)2, R = Ph (1a), Me (1b); [M] = Mn(CO)5, R = Ph (2); [M] = CpW(CO)3, R = Ph (3a), Me (3b); [M] = CpMo(CO)3, R = Ph (4)) as purple solids of different degrees of stability (1a, 1b, and 2 ? 3a, 3b, and 4). Treatment of 1a and 2 with CF3CO2H and alumina, respectively, leads to cleavage of the M-CH2 bond with the formation of (CO)3Co(μ-PhC2Me)Co(CO)3 and CpFe(CO)2OC(O)CF3 (from 1a). By contrast, 3a, 3b, and 4 react with CF3CO2H and alumina surprisingly to give heterobinuclear μ-alkyne complexes, Cp(CO)2M(μ-RC2Me)Co(CO)3 (5a, 5b, and 6, respectively) as air-stable, red solids. Complexes 1-6 were characerized by a combination of elemental analyses, FAB mass spectrometry, and IR and 1H and 13C NMR spectroscopy; the structure of 5a was determined by single-crystal X-ray analysis. Crystal data: monoclinic, space group P21/n with a = 8.825 (2) A?, b = 15.003 (2) A?, c = 14.035 (2) A?, β = 93.42 (1)°, and Z = 4. The structure was solved and refined to R = 0.0249 and Rw = 0.0268 by using 3918 independent reflections. The alkyne PhC2Me is transversely bridging the Co-W bond (2.693 (1) A?), and its Me substituent is trans to Cp.
