A new approach to the synthesis of carbon chains capped by metal clusters

Reactions of Co3(μ3-CBr)(μ-dppm)(CO)7 with {Au[P(tol)3]}2{μ-(CC)n} (n=2–4) have given {Co3(μ-dppm)(CO)7}{μ3:μ3-C(CC)nC} [n=2 (1), 3 (2), 4 (3)] containing carbon chains capped by the cobalt clusters. Tetracyanoethene reacts with 2 to give {Co3(μ-dppm)(CO)7}2{μ3:μ3-C(CC)2C[C(CN)2]C[C(CN)2]C} (4). X-ray structural characterisation of 1, 3 and 4 are reported, that for 3 being the first of a cluster-capped C10 chain.