Effect of rigidity of microenvironment on fluorescence of 7,7,8,8-tetracyanoquinodimethane (TCNQ)

We report the effect of rigidity of microenvironments on the fluorescence quantum yield(QY) of TCNQ dispersed in polymers which have different glass transition temperatures. The fluorescence QY decreases by increasing the temperature, which suggests that the nonradiative decay process is thermally activated. A pronounced ecrease in the fluorescence QY is observed when the transition occurs from the glass state to the rubber state. The fluorescence QYs in solvents that have the similar polarity to PMMA and PVAc are smaller than those for these polymers. It is demonstrated that the nonradiative decay process is accompanied by structural deformation