In this paper we present the results of an experimental study of the lowest 1S0→3P1 extravalence electronic excitation of atomic xenon in dense supercritical and subcritical fluid argon over the density range 0.1-1.4 g·cm-3, spanning the temperature region 80-300°K. Solvent perturbations were characterized in terms of the spectral shift, the linewidth and the first and the second moments of the absorption band. These energetic parameters exhibit a weak temperature sensitivity and a strong density dependence. The experimental data were analyzed in terms of the semiclassical theory of line broadening extended to account for guest-host and host-host correlations and incorporating realistic pair potentials in the ground and in the excited electronic states. The semiclassical theory results in manageable expressions for the first and for the second moments of the absorption band which are expressed in terms of a difference guest-host interaction potential together with the solute-solvent and the solvent-solvent radial distribution functions. The theory provides a semiquantitative account for the weak temperature dependence and for the marked density dependence of the energetic parameters specifying solvent perturbations and was utilized to extract quite reliable information concerning the excited state Xe(3P1)+Ar(1S0) potential.
|Number of pages||13|
|Journal||The Journal of Chemical Physics|
|State||Published - 1976|