Electron-mediated vibrational energy transfer

On the other hand, the similarity between metals is a characteristic of the electron-mediated vibrational energy transfer models. Here one must only calculate the population of excited electron-hole pairs at the energy of vibrational excitation, a quantity that is quite similar for many metals.b... 

Figure IS Two paths for energy flow from an electronically excited ethylene molecule to the water solvent, (a) Multistep energy transfer where the ethylene rotation acts as a mediator between the ethylene vibration and a single water solvent molecule, (b) Direct energy transfer from the ethylene vibration to a single water molecule. Adapted from ref. 119.

Fig. 10.3 The experimental results of NO vibration on metal or Li are shown. Loss of L5 eV within 100 fs on Au implies an electron-mediated process and almost no vibrational relaxation on the LiF insulating surface [23], (a) Plot of vibrational energy loss to an insulator and (b) metal surface for collisions of highly vibrationally excited NO. When NO is prepared in v = 12, eneigy transfer to LiF is approximately vibrationally elastic however, when NO is prepared in v= 15, collisions with Au(l 11) transfer an average of 1.3 eV to the surface (Reprinted with permission from ref [23]. 2000 AAAS.)...

Huang Y, Wodtke AM, Hou H, Rettner CT, Auerbach DJ (2000) Observation of vibration excitation and deexcitation for NO(v = 2) scattering from Au(lll) evidence for electron-hole-pair mediated energy transfer. Phys Rev Lett 84 2985-2988... 

Fig. 33 A Set-up of the redox-mediated tunneling experiment with a viologen-modified Au tip B schematic energy level diagram of a two-step ET process mediated by a redox-active molecule. The electron is transferred from the Fermi level of the substrate (left) ep,s to the LUMO of the molecule and after partial vibrational relaxation to the Fermi level of the tip ept (right). C Average ix vs. Eg curves recorded in constant bias spectroscopy mode, ixo = 0.1 nA, Ebias = 0.050 V. The sweep started in the stability region of V+ D average constant bias spectroscopy curve C after baseline correction. The blue line represents the fit using Eq. 8 with k = 0.42 eV, = 1.0, y = 1.0 [269]...

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