Laser Studies of Vibrational Energy Transfer

Chemical Laser Studies of Vibrational Energy Transfer 

A repetitively pulsed HF or DF chemical laser is used to excite either HF or DF to the V = 1 level in a fluorescence cell. A sufficient quantity of an inert diluent gas such as argon is employed in the cell to ensure rotational thermal-ization and to provide a buffer against diflFusive deactivation at the cell wall surfaces. Fluorescences from HF(v = 1) or DF(v = 1) levels, and fluorescences from the vibrational bands of admixed gases, are isolated by narrow-band interference filters. The temporal behavior of the fluorescence from a 

This type of experiment gives information concerning overall rates for vibrational energy transfer under conditions of rotational equilibrium. Information concerning rotational energy transfer must be obtained under conditions of rotational disequilibrium such experiments are much more difficult and have only recently been accomplished (see Section 3.3.4). 

The results of laser-induced fluorescence experiments can often be analyzed in terms of a simple two-level model in which V- V transfer between the laser-excited molecules (molecule 1) and a second admixed molecular species (molecule 2) is considered. In such a system the fluorescence intensities of vibrationally excited molecules of either species undergo temporal variations which are expressible in terms of two exponential time constants and The usual procedure for rate-constant determination 

Excellent review articles of vibrational energy transfer measurements with the laser-induced fluorescence technique have appeared recently. 

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Moore C B 1969 Laser studies of vibrational energy transfer Accounts Chem. Res. 2 103-9... 

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