Global and Local Models for Dilution Factors: Theory and Stimulated Emission Pumping Experiments

Abstract

The dilution factor is a measure of the intramolecular vibrational energy redistribution (IVR) an excited state undergoes. The distribution of dilution factors for a single molecule (SCCl2) was examined. Stimulated emission pumping (SEP) experiments were performed on SCCl2, probing the 7000--8,000 cm-1 range on the ground electronic state from first excited state and the 7,000--10,000+ cm-1 range from the second electronic state. An extended cross correlation analysis was applied to obtain more accurate measurements of dilution factors. Simulated SEP spectra were constructed according to two theoretical models: a globally random Golden Rule model and a locally random analytical model. Autocorrelation of the experimental and simulated differences revealed a simple and robust method of analyzing the distribution of dilution factors within a spectrum.