193222-30-9Relevant academic research and scientific papers
Oxidation of ruthenium hydrides (η5-C5H4R)Ru(PPh3)2H (R=H, tBu, CH2Ph, CTol3). X-ray crystal structure determination of (η5-C5H4(CTol3))Ru(PPh 3)2H and an electrochemical study of its stable cation radical
R?mming, Christian,Smith, Kjell-Tore,Tilset, Mats
, p. 281 - 290 (2008/10/08)
The oxidation of a series of cyclopentadienylruthenium hydrides (η5-C5H4R)Ru(PPh3)2H (R=H, tBu, CH2Ph, CTol3, CPh2(p-MeOC6H4)) has been investigated by cyclic voltammetry. For R=H, tBu and CH2Ph, uncomplicated reversible oxidation processes are observed. For the trityl-substituted species (R=CTol3, CPh2(p-MeOC6H4)), the cyclic voltammograms indicate the presence of two isomeric cation radicals that exist in a dynamic equilibrium. It is suggested that this may be the result of an interaction between the 17-electron Ru center in the cation radical and the π system in one aromatic ring to yield a weakly bonded 19-electron adduct of the cation radical. The first ESR spectroscopic data for a 17-electron cyclopentadienylruthenium hydride cation radical are reported for (η5-C5H4(CTol3))Ru(PPh 3)2H+. The anisotropic ESR spectra showed no hyperfine structure. The X-ray crystal structure of the neutral hydride (η5-C5H4(CTol3))Ru(PPh 3)2H reveals a sterically crowded molecule in which the trityl group eclipses the hydride ligand. Two tolyl groups on the CTol3 ring substituent are on the same side of the Cp ring plane as the metal and induce steric repulsions in the molecule. Crystal data for (η5-C5H4(CTol3))Ru(PPh 3)2H: space group P-1, a=11.3505(3), b=14.3263(3), c=17.3172(4) A?, α=102.005(1), β=98.348(1), γ=112.321(1)°, T=170 K, R1 (F>4σ(F))=0.067, wR2(1>2σ(1))=0.128.
