Knowledge Bank

The fluorescence excitation and dispersed fluorescence spectra of supersonically cooled p-hydroxy-trans-stilbene, p-methoxy-trans-stilbene, and the para-substituted methyl-trans-stilbenes will be presented. The spectra of the hydroxy and methoxy compounds are nearly identical but their water complexes show different shifts. The effects on the methyl barrier, owing to the ability of the hydroxy to act as a proton donor, will be discussed.