Solvent effect on the absorption spectra

fluorescence spectra and fluorescence quantum yield were studied.In particular

the fluorescence quantum yields for Rh6G in hydrogen bond solvents were discussed.By using variation excited methods the fluorescence quantum yields were approximate.The linear variation between the fluorescence quantum yield of Rh6Gsolutions and the polarity(ε-1)/(2ε+1)of the solvents was found.It was alsofound that the same relationship between the fluorescence quantum yields

lifetimes and the polarity(ε-1)/(2ε+1)in ANS.Fluorescence quantum yields forRh6G and ANS in hydrogen bond solvents decreased with increase of solvent polarity(ε-1)/(2ε+1).The solvent effect on fluorescence quantum yield for Rh6G in hydrogen bond solvents could be interpreted by the energy dissipation.In the case of strong interaction between the molecules Rh6G and the hydrogenbond solvent molecules with high(ε-1)/(2ε+1)

the energy dissipated quickly.Whereas in those low(ε-1)/(2ε+1)solvents

the energy dissipated less rapidly.This paper's results show that the η

2/3

(η-viscosity)dependence

which was first proposed by Forster and was experimentally verified for the quantum yield and fluorescence lifetimes of several triphenyl methane dyes

did not coincide with Rh6G in hydrogen bond solvents as well as ANS solution.