Solubility and fluorescence lifetime of 2,5-diphenyloxazole and 1,4-bis(5-phenyl-oxazolyl-2)benzene in water-ethanol and water-acetone solvent systems

摘要

The solubility of two luminophores, 2,5-diphenyl-1,3-oxazole (PPO) and 1,4-bis(5-phenyl-oxazolyl-2) benzene (POPOP), has been determined in water-acetone and water-ethanol solvent systems at 25.0 degrees C. The excited states of PPO and POPOP have been studied in these mixed solvents. The dependence of fluorescence lifetime and solubility on mixed solvents composition is discussed in terms of solvation of luminophore molecules. The multiple linear regression analysis of fluorescence lifetime and solubility dependences on solvent polarity parameters has been carried out. Equations, describing the dependence of solubility and fluorescence lifetime of luminophores on solvent parameters, are presented. It has been revealed that both solubility of PPO and POPOP and their fluorescence lifetimes are controlled mainly by the energy of cavity formation.