Energy disposal in the two-photon laser-assisted reaction in xenon and chlorine gas mixtures

• Published in: The Journal of chemical physics 2000-12, Vol.113 (23), p.10551-10559
• Main Authors: Kohel, J., Keto, J. W.
• Format: Article
• Language: English
• ISSN: 0021-9606; 1089-7690
• DOI: 10.1063/1.1324976

The two-photon laser assisted reaction (LAR) in low pressure xenon and chlorine gas mixtures has been studied over a broad range of excitation wavelengths in order to characterize the role of the entrance channel in determining the vibrational state distribution of the reaction products. We measure a high degree of vibrational excitation in the XeCl* product, confirming observations from previous studies of the LAR of Xe+Cl2 collision pairs [Ku et al., J. Phys. Chem. 87, 2989 (1983)], and in distinct contrast with the vibrationally cold excimer observed following laser excitation in molecular beam experiments [Boivineau et al., Chem. Phys. Lett. 128, 528 (1986)]. The mean vibrational energy in the XeCl excimer depends strongly on laser wavelength, increasing with decreasing wavelength. Moreover, an increasing fraction of the available energy from the reaction is observed as vibration in the XeCl* product as the laser is tuned toward shorter wavelengths. The reaction outcomes are interpreted in terms of a selectivity of initial conditions on the ionic potential surface that mediates the reactive collision.