Dual fluorescence of 4-dialkylaminopyridines under supersonic jet conditions

The results of the spectral and photophysical investigations of 4-dimethylaminopyridine (DMAP), 4-diethylaminopyridine (DEAP), 4-diisopropylaminopyridine (DIAP) and their 1:1 complexes with alcohols under supersonic jet conditions by LIF, R2PI and IR/R2PI techniques are presented. The dispersed emission spectra of jet-cooled DMAP, DEAP and DIAP, recorded upon selective excitation in the 0 0 0 region, are attributed mostly to the radiative transition from the primary excited state. In the case of DIAP the higher energy excitation results in an appearance of the long-wave fluorescence. The low-energy luminescence band is observed also for the complexes of DEAP and DIAP with alcohols of relatively strong acidity.