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

Reactions Of Co-3(mu(3)-CBr)(mu-dppm)(CO)(7) with {Au[P(tol)(3)]}(2)[mu-(CdropC)(n)} (n=2-4) have given {Co-3(mu-dppm)(CO)(7)}{mu(3):mu(3)-C(Cdrop C)(n)C} [n = 2 (1), 3 (2), 4 (3)] containing carbon chains capped by the cobalt clusters. Tetracyanoethene reacts with 2 to give {Co-3(mu-dppM)(CO)(7)}(2){mu(3):mu(3)-C(CdropC)(2)C[=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 C-10 chain. (C) 2003 Elsevier Science B.V. All rights reserved.