LIFETIME-LIMITED PHOTOCHEMICAL HOLE-BURNING DJ s-TETRAZINE-BENZENE MIXED CRYSTALS AT 2 K

We show that the technique of photochemical hole-burning can be utilized to measure sub-nanosecond fluorescence liie-times of molecular excited states. s-tetrazine is taken as an example and from the width of the hole (0.7 * 0.1 GHz), burned in the origin of the lowest t Bju *- lArg transition at 2 K in a benzene mixed crystal, a fluorescence lifetime of 455+< % ps is obtained _ The coherence lifetime of the 16 ai vibronic transition is found to be 25 ps. 1