17141-01-4Relevant academic research and scientific papers
Intramolecular combination of vinyl, aryl and carbonyl ligands in ruthenium(II) complexes: a mechanistic study
Waugh, Martin P.,Mawby, Roger J.
, p. 21 - 34 (2007/10/03)
Complexes underwent competing isomerisation reactions, one an intramolecular construction of a vinyl aryl ketone which remains co-ordinated, the other a simple redistribution of the ligands around the metal.Product ratios are determined by kinetic rather than thermodynamic factors.For a sequence of complexes with L = L' = PMe2Ph, electron-releasing substituents on the vinyl ligand favour formation of ketone complexes, whereas similar substituents on the phenyl ligand have the reverse effect.Increasing the reaction temperature disfavours ketone complex formation.Mechanisms involving initial migration of either the vinyl or the aryl ligand are discussed on the basis of these results and a complementary study involving trapping of the likely acyl intermediates.
Alkyne Insertion into Ruthenium-Carbon Bonds: Formation and Ring-closing Reactions of Vinyl Complexes
Crook, Joseph R.,Chamberlain, Barbara,Mawby, Roger J.
, p. 465 - 470 (2007/10/02)
Compounds react with to yield vinyl complexes (2a)-(2d).The mechanism of formation appears to involve CO substitution by the alkyne, combination of alkyne a
Kinetic and thermodynamic stabilities of the geometric isomers of (R3P)2Ru(CO)2Cl2 and (R3P)3Ru(CO)Cl2 complexes
Krassowski, Daniel W.,Nelson, John H.,Brower, Kay R.,Hauenstein, Dale,Jacobson, Robert A.
, p. 4294 - 4307 (2008/10/08)
A series of ruthenium(II) complexes of the type RuCl2(CO)2P2 (P = Bzl3P, Ph3P, Ph2MeP, PhMe2P, Me3P) have been prepared and characterized by elemental analyses, physical properties, infrared spectroscopy, UV-visible spectroscopy, and 1H, 13C{1H} and 31P{1H} NMR spectroscopy. The first-formed complex, with all ligand pairs trans (ttt), thermally isomerizes in solution to produce the isomer with all ligand pairs cis (ccc). This ccc isomer further isomerizes in solution to produce the thermodynamically preferred isomer with only the phosphine ligands trans (cct). The size and basicity of the phosphine affect the isomerization rate, which increases with an increase in size and a decrease in phosphine basicity and proceeds by initial dissociation of carbon monoxide. Activation parameters, ΔS? and ΔV?, are both positive for the ttt-ccc isomerization consistent with a dissociative process. Negative values of ΔS? for the ccc → cct isomerization suggest that an associative step may be important, cis- and trans-RuCl2(CO)P3 complexes with meridionally coordinated phosphines (P = Me3P, PhMe2P, Ph2MeP) were also prepared and characterized by the same methods. The first-formed isomer with trans chlorides thermally isomerizes in solution to the thermodynamically stable isomer with cis chlorides. Positive values of both ΔS? and ΔV? are consistent with a dissociative process. Phosphine inhibition of this isomerization indicates initial phosphine dissociation. The crystal structures of cis(1)- and trans-RuCl2(CO)(Ph2MeP)3 (1 and 2, respectively) have been determined by counter methods. Compound 1 crystallizes in space group P1 with a = 16.158 (4) A?, b = 18.361 (3) A?, c = 13.170 (4) A?, α = 93.36 (2)°, β = 108.03 (3)°, γ = 90.75 (2)°, and Z = 4. Compound 2 crystallizes in space group P21/c with a = 20.373 (9) A?, b = 9.831 (5) A?, c = 20.689 (7) A?, β = 117.43 (3)°, and Z = 4. Both structures were refined by least-squares methods with R = 0.093 for 1 and R = 0.069 for 2 for 4614 and 2974 unique reflections with I/σ(I) ≥ 3.0 for 1 and 2, respectively. The bond distance of the phosphine trans to carbon monoxide in the trans isomer (d(RuP) = 2.490 (4) A?) is longer than the other two Ru-P distances (2.403 (4) A?). The 31P{1H} NMR data also suggest that this phosphine is relatively weakly bound and so this phosphine likely dissociates as the first step in the geometric isomerization.
Preparation, Isomerization, and Reactions of Hydride Complexes of Ruthenium(II)
Bray, Joanne M.,Mawby, Roger J.
, p. 2989 - 2994 (2007/10/02)
Hydride complexes 2> (X = H or Cl, L = PMe2Ph or AsMe2Ph) and their deuteride analogues have been prepared.The complex exists in solution as an equilibrium mixture of isomers.The dideuteride exchanges with H2 in solution: no is formed, suggesting that exchange occurs via .Exchange also occurs with ethene and propene: here is observed.Ethene is hydrogenated by 2>, with formation of ethane and complexes 2>, which are reconverted to 2> by H2.The terminal alkenes 1-hexene and 3-phenylpropene are isomerized by 2>: for L = AsMe2Ph, a little hydrogenation of 3-phenylpropene also occurs.
