Download or read book Synthesis and Reactivity of Ruthenium and Platinum Complexes with Non-dative Heteroatomic Ligands: Studies of Carbon-hydrogen Bond Activation written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Several ruthenium complexes with non-dative heteroatomic ligands were prepared and fully characterized, including TpRu(PMe3)2X (X = OH, OPh, OMe, SH; Tp = hydridotris(pyrazolyl)borate). At elevated temperatures (90 °C -- 130 °C), complexes of the type TpRu(PMe3)2X (X = OH, OPh, Me, Ph or NHPh) undergo regioselective HD exchange with deuterated arenes. In addition, for X = OH or NHPh, HD exchange occurs at hydroxo and anilido ligands, respectively. For X = OH, OPh, Me, Ph or NHPh, isotopic exchange occurs at the Tp 4-positions with only minimal deuterium incorporation at the Tp 3- or 5-positions. TpRu(PMe3)2Cl, TpRu(PMe3)2OTf (OTf = trifluoromethanesulfonate) and TpRu(PMe3)2SH do not initiate HD exchange in C6D6 after extended periods of time at elevated temperatures. Mechanistic studies indicate that the likely pathway for the HD exchange involves ligand dissociation (PMe3 or NCMe), Ru-mediated activation of an aromatic C-D bond, and deuteration of basic heteroatomic ligand (hydroxo or anilido) or Tp positions via intermolecular D+ transfer. The Ru(II) complexes TpRu(PMe3)2OR (R = H or Ph) react with excess phenylacetylene at elevated temperatures to produce the phenylacetylide complex TpRu(PMe3)2(CðCPh). Kinetic studies indicate that the reaction of TpRu(PMe3)2OH and phenylacetylene likely proceeds through a pathway that involves TpRu(PMe3)2OTf as a catalyst. The reaction of TpRu(PMe3)2OH with 1,4-cyclohexadiene at elevated temperature forms benzene and TpRu(PMe3)2H, while TpRu(PMe3)2OPh does not react with 1,4-cyclohexadiene even after 20 days at 85 °C. The paramagnetic Ru(III) complex [TpRu(PMe3)2OH][OTf] is formed upon single-electron oxidation of TpRu(PMe3)2OH with AgOTf. Reactivity studies suggest that [TpRu(PMe3)2OH][OTf] initiates reactions, including hydrogen atom abstraction, with C-H bonds that have bond dissociation energy d"82 kcalD ol. Experimentally, the O-H bond strength of the Ru(II).