Transition metal complexes of substituted alkynes. VI. Substituent arrangement in some bridging tris(alkyne)-cobalt complexes

Abstract

The new organocobalt complex CO2(CO)4(CF3C2CF3)2(CF3C2H) has been isolated from the reaction of hexafluorobut-2-yne with p-trifluoropropyne-hexacarbonyldicobalt. In addition, a second isomer of the known complex CO2(CO)4(CF3C2CF3)2(CF3C2H)2 has been isolated from the reaction of 3,3,3-tri-fluoropropyne with p-hexafluorobut-2-yne-hexacarbonyldicobalt. A detailed study of the 1H and 19F N.M.R. spectra of these and the related complexes Co2(C0)4- (CF3C2CF3)3 and CO2(CO)4(CF3C2H)3 has led to an assignment of the substituent arrangement in all of these complexes.