Heterometallic complexes containing 1,1′-(CC)2Fc′ units linking two different metal centres

Proto-desilylation of 1-(Me3SiCC)-1′-{Cp∗(dppe)RuCC}Fc′ (1) afforded the corresponding ethynyl derivative 2, from which the green Co2(μ-dppm)n(CO)8−2n (n = 0, 1) adducts 3 and 4 were obtained. Replacement of the ethynyl proton in reactions between 2 and AuCl(PPh3), Hg(OAc)2 or FeCl(dppe)Cp∗ gave complexes 1-(RCC)-1′-{Cp∗(dppe)RuCC}Fc′ [R = Au(PPh3) 5, 1/2Hg 6, Fe(dppe)Cp∗8]; the latter gave bis-vinylidene 9 with MeI, characterised (as was 2) by a single crystal X-ray study. Oxidative coupling of 2 (CuCl/tmeda/acetone, air) gave diyne 10, while coupling of 5 with Co3(μ3-CBr)(μ-dppm)(CO)7 afforded 1-{Cp∗(dppe)RuCC}-1′-{(OC)7(μ-dppm)Co3(μ3-CCC)} Fc′ (11).