title: Aqueous coordination chemistry of H2: why is coordinated H2 inert to substitution by water in trans-Ru(P2)2(H2)H+-type complexes (P2 = a chelating phosphine)?
abstract: The reactivity of a series of trans-Ru(P(2))(2)Cl(2) complexes with H(2) was explored. The complexes reacted with H(2) via a stepwise H(2) addition/heterolysis pathway to form the trans-[Ru(P(2))(2)(H(2))H](+) dihydrogen complexes. Some of the resulting eta(2)-H(2) complexes were surprisingly inert to substitution by water, even at concentrations as high as 55 M; however, the identity of the bidentate phosphine ligand greatly influenced the lability of the coordinated eta(2)-H(2) ligand. With less electron-donating phosphine ligands, the H(2) ligand was susceptible to substitution by H(2)O, whereas with more electron-rich phosphine ligands, the H(2) ligand was inert to substitution by water. Density functional theory (DFT) calculations of the ligand substitution reactions showed that the Ru-H(2) and Ru-H(2)O complexes are very close in energy, and therefore slight changes in the donor properties of the bidentate phosphine ligand can inhibit or promote the substitution of H(2)O for H(2).
authors.affiliation: Department of Chemistry, University of Oregon, Eugene, Oregon 97403, USA.
authors.forename: Nathaniel K
authors.initials: NK
authors.lastname: Szymczak
authors.forename: Dale A
authors.initials: DA
authors.lastname: Braden
authors.forename: Justin L
authors.initials: JL
authors.lastname: Crossland
authors.forename: Yevgeniya
authors.initials: Y
authors.lastname: Turov
authors.forename: Lev N
authors.initials: LN
authors.lastname: Zakharov
authors.forename: David R
authors.initials: DR
authors.lastname: Tyler
mesh_terms: D003198:Computer Simulation; D018360:Crystallography, X-Ray; D006859:Hydrogen / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D010720:Phosphines / Q000737:chemistry*; D012428:Ruthenium / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D009942:Organometallic Compounds; D010720:Phosphines; D014867:Water; D012428:Ruthenium; D006859:Hydrogen; C044646:phosphine