Significant vibrational structures of fluorescence emission of excimers of 1,3-di(a-naphthyl)propane (1) in 1:1 methanol-water binary solvent was induced by the addition of RNA or its constitutive bases. It is suggested that RNA and base mols. induce the 1 mols. to freeze with proper conformation and give a definite excited vibration, and this process was promoted by hydrophobic effect. Inductive vibrational structure formation can be prevented by the addition of b-cyclodextrin, but is not disturbed by the addition of a-cyclodextrin, indicating partial inclusion of 1 mols. by b-cyclodextrin.

Key words: FLUORIMETRIC ANALYSIS, RIBONUCLEIC ACID, SOLVENTS, CYCLODEXTRIN, INDUCER, FLUTTER ANALYSIS, EXCIMER, CLATHRATES, STRUCTURE, MICROENVIRONMENTAL EFFECTS