A novel route to butatrienylidene complexes: Stabilisation 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 [RU(5){mu(4)-CCCCH(SiMe(3))}(mu-PPh(2))(2)(mu-SMe)(mu(3)-SMe)(CO)(10)] 2, alkaline hydrolysis of which gives the first stable butatrienylidene complex [Ru-5(mu(4)-CCCCH2)(mu-PPh(2))(2)(mu-SMe)(mu(3)-SMe)(CO)(10)] 3; carbonylation of 3 affords produces the spiked-rhomboidal pentanuclear complex [Ru-5(mu(5)-CCCCH2)(mu-PPh(2))(2)(mu-SMe)(2)(CO)(11)] 4; the X-ray structures of 3 and 4 are reported.