Edge excitation red shift and micro environmental effects on the photophysics of quinine bisulphate dication

Photophysical properties of quinine bisulphate dication (QSD) in polymer ma trices viz, polymethyl methacarylate (PMMA), cellulose acetate (CA), Nafion (R)-117 and polyvinyl alcohol (PVA) along with a comparative study in fluid media (frozen glass) has been reported. Edge excitation red shift (EERS) i s observed in all these media. The magnitude of EERS increases in the froze n glass as compared to liquid phase. The polymers also differ in the magnit ude of EERS, The results suggest the presence of the molecule in different geometries in the polymeric media. The photophysical behavior has been foun d to be sensitive to the micro-environmental polarity and free volume of th e matrix. (C) 1999 Elsevier Science S.A. All rights reserved.