Synthesis of triruthenium clusters containing mixed bridging phosphido ligands: X-ray crystal structures of [Ru-3(CO)(7)(mu-H)(mu-PBu2t)(mu-PCy2)(2)] and the electron-deficient complex [Ru-3(mu-CO)(CO)(5)(mu-H)(2)(mu-PBu2t)(2)((Bu2PH)-P-t)]

摘要

The reaction of the triruthenium cluster [Ru-3(CO)(8)(mu-H)(2)(mu-PBu2t)(2)] (1) with Cy2PH has been investigated. Complex 1 reacts spontaneously with the phosphine in toluene at room temperature. Subsequent heating under reflux for a short time affords the two novel mixed phosphido-bridged complexes [Ru-3(CO)(7)(mu-H)(mu-PBu2t)(mu-PCy2)(2)] (2) and [Ru-3(CO)(8)(mu-H)(2)(mu-PBu2t)(mu-PCy2)] (3) in good yields beside the electron-deficient 46-electron cluster [Ru-3(mu-CO)(CO)(5)(mu-H)(2)(mu-PBu2t)(2)((Bu2PH)-P-t)] (4) as minor product. Compound 1 reacts with stoichiometric amounts of (Bu2PH)-P-t to give 4 in nearly quantitative yield. The metal cluster 2 was also synthesized directly by reaction of [Ru-3(CO)(8)(mu-H)(2)(mu-PCy2)(2)] (5) With (Bu2PH)-P-t in refluxing toluene. 5 reacts with Ph2PCH2PPh2 (dppm) in toluene under reflux to give [Ru-3(CO)(6)(mu-H)(2)(mu-PCy2)(2)(mu-dppm)] (6), but is formed only in traces under these conditions. The characterization of the compounds 2, 3 and 4 was carried out by spectroscopic means and the X-ray crystal structures of 2 and 4 are reported. (C) 1998 Elsevier Science S.A. [References: 40]