A NOVEL ROUTE TO BUTATRIENYLIDENE COMPLEXES - STABILIZATION OF C=C=C=CH2 ON RU-5 CLUSTERS

Addition of C-2(SiMe(3))(2) to RU(5)(mu(5)-C-2)(mu-PPh(2))(2)(mu-SMe)( 2)(CO)(11)] 1 affords an isomeric mixture of iMe(3))}(mu-PPh(2))(2)(mu -SMe)(mu(3)-SMe)(CO)(10)] 2, alkaline hydrolysis of which gives the fi rst stable butatrienylidene complex -CCCCH2)(mu-PPh(2))(2)(mu-SMe)(mu( 3)-SMe)(CO)(10)] 3; carbonylation of 3 affords produces the spiked-rho mboidal pentanuclear complex -5(mu(5)-CCCCH2)(mu-PPh(2))(2)(mu-SMe)(2) (CO)(11)] 4; the X-ray structures of 3 and 4 are reported.