SYNTHESIS AND CHARACTERIZATION OF THE FIRST RUTHENIUM-LEAD CLUSTERS, [RU-3(MU-PBR(2))(MU-CO)(2)(CO)(9)] AND [RU-3(MU-PBR(2))(2)(MU-CO)(CO)(9)] - SINGLE-CRYSTAL X-RAY STRUCTURE OF [RU-3(MU-PBR(2))(2)(MU-CO)(CO)(9)]

Reaction of PbR(2) [R = CH(SiMe(3))(2)] with [Ru-3-(CO)(12)] at 60 degrees C afforded the first ruthenium-lead clusters [Ru-3(mu-PbR(2))(mu-CO)(2)(CO)(9)] (1) and [Ru-3(mu-PbR(2))(2)-(mu-CO)(CO)(9)] (2). After separation the compounds were characterized by H-1 and C-13 NMR and IR spectroscopies, FAB-MS, and, for 2, by a single-crystal X-ray study. The structure gives the first reported Ru-Pb bond lengths and shows the cluster to have a planar pentametallic array with two PbR(2) and one CO bridging the three sides of an Ru-3 triangle. A greatly improved yield for the preparation of PbR(2) is also reported. Compound 2 crystallizes in the triclinic space group PI with unit cell dimensions a = 12.279(6) Angstrom; b = 15.406(6) Angstrom, c = 20.775(5) Angstrom, alpha = 99.54(6)degrees, beta = 107.47(6)degrees, gamma = 109.59(6)degrees, U = 3373.1(10) Angstrom(3), and Z = 2. A total of 10179 unique observations gave a merging R of 0.038 and a conventional R of 0.0756.