Knowledge Bank

The van der Waals complex, pDFB$\cdots$Ar, as observed in a supersonic expansion is characterized by well depths of $348cm-1$ and $378cm-1$ in $SO$ and $S1$ states, respectively. Diapersed emission spectra obtained after pumping each of five absorption bands ranging to $1250cm-1$ of vibrational energy in the electronically excited complex are comprised of $S1\to SO$ fluorescence from the complex and $S1\to SO$ fluorescence from the uncomplexed pDFB indicating that predissociation lifetimes are competative with the 10 nsec fluorescance lifetimes. The identification of vibrational product states of the uncomplexed pDFB show that few of the energetically available channels are used when the complex predissociates. The observed competition among possible predissociation channels is compared to a predictive model for collision-induced vibrational energy flow in $S1$ pDFB.