Photochemical studies of rhodamine R.6G in ethanol solutions using laser flash photolysis

A stable photodecomposition product (P) of the rhodamine 6G (R.6G) dye dissolved in ethanol solution, has been investigated using flash photolysis techniques. The reactions involved in the formation of this photo-product were investigated in detail. Results indicate (a) that the predominant mechanism, for the formation of this species probably involves the reaction of a species X (which is not the R.6G triplet) with R.6G ground state molecules, i.e., X + R.6G → P, and (b) that species X is probably formed via a H-atom abstraction reaction involving the solvent and excited states of the R.6G dye or solvent impurities.