162228-66-2Relevant academic research and scientific papers
Synthesis, Crystal Structures and Reactivity of Ruthenium-(II) and -(III) Complexes containing β-Ketophosphine or Phosphino Enolate Ligands
Braunstein, Pierre,Chauvin, Yves,Naehring, Jens,Dusausoy, Yves,Bayeul, Daniel,et al.
, p. 851 - 862 (2007/10/02)
Reaction of 1, 2 or 3 equivalents of (diphenylphosphino)acetophenone, Ph2PCH2C(O)Ph (L), with in toluene afforded selectively 1, 2 or 3, respectively.Complex 1 hydrogenates and isomerises hex-1-ene at atmospheric hydrogen pressure, whereas 2 is inactive.Complex 3 exhibits a dynamic behaviour on the 1H NMR time-scale which corresponds to exchange between chelating and terminally bound phosphines.The activation energy of this process was calculated to be 63.7 +/- 0.7 kJ mol-1.Reaction of 3 with TIPF6 in CH2Cl2 gave 9 which reacted with a second equivalent of TIPF6 in MeCN to give the dicationic complex 10.The fac and mer isomers of the tris(enolato) Ru(II) complex 11a and 11b were obtained by reaction of 9 with NaH in tetrahydrofuran (thf).Treatment of 3 with NaOMe in toluene afforded selectively 11b, which has been crystallised by addition of 1,4,7,10,13-pentaoxacyclopentadecane (15-crown-5) to give 12.Protonation of 11b with HBF4*Et2O gave the neutral intermediate 13, characterised spectroscopically, and the final product 14.Treatment of with 2 equivalents of L yielded the ruthenium(III) complex 15, which was easily reduced to the ruthenium(II) complex 2.The solid state structures of complexes 2, 10 and 12 have been determined by single crystal X-ray analysis.The co-ordination of the metal in 2 and 10 is slightly distorted octahedral with the two phosphorous atoms (and oxygen atoms) in a cis position and the chloride and acetonitrile ligands, respectively, in a trans position.In the chiral anion of complex 12 the distorted octahedral structure has a meridional arrangement of the P atoms and electronic delocalisation occurs within the chelating phosphino enolate ligands.
