Synthesis and structure of metallocarbon clusters bearing pendant ethynyl ligands. X-ray crystal structures of Os-3(CO)(9)(mu-CO)(mu(3)-eta(1),eta(1),eta 2-Me3SiC CC2C CSiMe3), Os3Ru(CO)(12)(mu(4)-eta(1),eta(2),eta(1),eta(2)-Me3SiC CC2C CSiMe3), Ru-4(CO)(12)(mu(4)-eta(1),eta(2),eta(1),eta(2)-Me3SiC CC2C CSiMe3) and {Ru-4(CO)(12)}{Co-2(CO)(6)}(mu(4)-eta(1),eta(2),eta(1),eta(2):mu-eta(2),eta(2)-Me3SiC2C CC2SiMe3)

The reaction of 1,6-bis(trimethylsilyl)hexa-1,3,5-triyne (1) with Os-3(CO)( 10)(NCMe)(2) yields Os-3(CO)(9)(mu-CO)(mu(3)-eta(1), eta(1), eta(2)-Me3SiC= CC2C=CSiMe3) (2), which on treatment with Ru-3(CO)(12) gives Os3Ru(CO)(12)( mu(4)-eta(1), eta(2), eta(1), eta(2)-Me3SiC=CC2C=CSiMe3) (3). In the case o f the reaction between 1 and Ru-3(CO)(12) the major products are the butter fly cluster Ru-4(CO)(12)(mu(4)-eta(1), eta(2), eta(1), eta(2)-Me3SiC=CC2C=C SiMe3) (4) and the ruthenole complex Ru-2(CO)(6){mu-eta(2), eta(5)-C(C=CSiM e3)C(C=CSiMe3)C(C=CSiMe3)C(C=CSiMe3)C(C=CSiMe3)} (5). Cluster 4 reacts with Co-2(CO)(8) to give {Ru-4(CO)(12)}{Co-2(CO)(6)}(mu(4)-eta(1), eta(2), eta( 1), eta(2):mu-eta(2), eta(2)-Me3SiC2C=CC2SiMe3) (6) in which the butterfly cluster core has slipped along the hexatriyne chain. (C) 1999 Elsevier Scie nce S.A. All rights reserved.