Metal-hydrogen vibrational modes

Metal-hydrogen vibrations have been reported for hydrogenated RuS2 (540 and 820 cm ) [130] but metal-hydrogen vibrations have not been observed for M0S2 or WS2. 

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Fig. 3 Lifetimes associated with the hydrogen vibrational mode perpendicular to a Pd(Ul) surface in different adsorption sites. The circles are the state-to-state inverse transition rates from a given initial state. The total lifetimes are represented by full squares and the harmonic scaling law is depicted as a solid line. The quantum numbers are determined by visual inspection of one-dimensional cuts of the wave functions integrated over all remaining coordinates. For computation of the rates usihg eqn (20), the embedding density is chosen as that of the pure metal. Reproduced with permission from ref. 47.

The hydrogenation is catalysed by nickel and other transition metals. Vibrational spectroscopy (infrared, HREELS, INS) has been applied to determining the orientation and binding of benzene on the catalyst surface. We suimnarise INS studies of benzene, adsorbed benzene and model complexes. The intensities and frequencies of the vibrational modes are computed by the Wilson GF method. The benzene molecule... 

We shall summarise the INS spectra of H-S and H-metal species in sulfides, undissociated dihydrogen, and adsorbed thiophene and benzothiophenes. Lattice vibrations of the sulfides are relevant because they appear in the hydrogen riding modes. 

P.C.H. Mitchell, A.J. Ramirez-Cuesta, S.F. Parker, J. Tomkinson D. Thompsett (2003). J. Phys. Chem. B, 107, 6838-6845. Hydrogen spillover on carbon-supported metal catalysts studied by inelastic neutron scattering. Surface vibrational states and hydrogen riding modes. 

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