C-C COUPLING REACTIONS ON A FLEXIBLE RU3PT FRAMEWORK - X-RAY CRYSTAL-STRUCTURES OF RU3PT[MU(4)-C(BU-T)C(H)C(C(BU-T)) (C(H)C(BU-T))](MU-SIGMA-PI-C(H)=C(H)(BU-T)) (CO)(7)(DPPE), RU3PT[MU(3)-C(BU-T)CC(BU-T)CH2] (CO)(8)(DPPE) AND RU3PT(MU(4)-C(PH)CCC(H)(BU-T)) (MU(4)-TE)(MU-TEPRI)(CO)(6)(DPPE)

Reaction of Ru3Pt (mu-H) {mu(4)-C drop C(Bu')} (CO)(9)(dppe) (1) with excess HC drop CBu' afforded three C-C coupled products, -C(Bu')C(H)C{ C(Bu')}{C(H)C(Bu')}]{mu-sigma-pi-C(H) = C(H)(Bu')}(CO)(7)(dppe) (3), a nd an inseparable mixture of the trans- and gem-isomers of Ru3Pt[mu-C( Bu')CC(Bu').CH2](CO)(8)(dppe) 4a. Single crystal X-ray structure deter minations of 3 and gem-4a were undertaken. Cluster 3 contains an Ru,Pt chain-skeleton with three metal-metal bonds and incorporates three mo lecules of HC drop CBu' as a sigma-pi-vinyl ligand and an unusual C-C coupled ligand. Cluster gem-4a contains a tetrahedral Ru,Pt skeleton w ith a C-C coupled vinyl-alkyne ligand. Reaction of 1 with HC drop CR, R=Ph and SiMe3 gave similar products 4b and 4c respectively, with evid ence for all three possible isomers cis-, trans-, and gent, while reac tion of 1 with PhC=CPh gave the expected cis-, trans mixture of isomer s of 4d. Treatment of 1 with PrTeC drop CPh afforded two isomers of Ru 3Pt{mu(4)-C(Ph)CCC(H) (Bu')} (mu(4)-Te) (mu-TePr')(CO)(6)(dppe) (5) as an inseparable mixture. A single crystal X-ray structure determinatio n of the isomer trans-5 was undertaken. The Ru,Pt skeleton consists of a distorted square plane with a mu(4)-capping tellurium atom. The C-C coupled ligand mu(4)-C(Ph)CCC(H)(Bu') is bonded in an unusual fashion to all four metal atoms, and can be thought of as a metallated vinyl- alkyne. (C) 1998 Elsevier Science Ltd. All rights reserved.