Electron-mediated vibrational energy

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... 

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.)...

Vibrationally mediated photodissociation (VMP) can be used to measure the vibrational spectra of small ions, such as V (OCO). Vibrationally mediated photodissociation is a double resonance technique in which a molecule first absorbs an IR photon. Vibrationally excited molecules are then selectively photodissociated following absorption of a second photon in the UV or visible [114—120]. With neutral molecules, VMP experiments are usually used to measure the spectroscopy of regions of the excited-state potential energy surface that are not Franck-Condon accessible from the ground state and to see how different vibrations affect the photodissociation dynamics. In order for VMP to work, there must be some wavelength at which vibrationally excited molecules have an electronic transition and photodissociate, while vibrationally unexcited molecules do not. In practice, this means that the ion has to have a... 

Experimentally one can investigate resonances by various spectroscopic schemes, as indicated in Fig. 1 by direct overtone pumping [11] from the ground vibrational state, by vibrationally mediated photodissociation [12] using an excited vibrational level as an intermediate, or by stimulated emission pumping (SEP) [13-15] from an excited electronic state. In all cases it is possible to scan over a resonance and thereby determine its position j4s aHd its width hkU). A schematic illustration of an absorption or emission spectrum is depicted on the left-hand side of Fig. 1 all of the more or less sharp structures at energies above threshold are resonances. Figure 2 shows an overview SEP spectrum measured for DCO [16]. It consists of... 

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