Photobehavior of pyrene end-labelled poly(ethylene oxide) in methanol-water mixtures

The photobehavior of pyrene end-labelled poly(ethylene oxide) and methyl 4-(3-pyrenyl)-butyrate was studied in methanol, water and methanol-water mixtures. It was found that the solvent dependence of the pyrene lifetime in the polymer is different from that of the unbonded molecule. The results are discussed in terms of specific solvation effects on the chromophore in the polymer and it is emphasized that these effects must be taken into account when the photobehavior of an unbonded molecule is taken as a model for that of an isolated chromophore in a polymer.