Solvent Effect on the Photophysical Properties of Squarylium Cyanine Dye

In this report the solvent effects on the photophysical properties of squarylium cyanine dye with indolence heterocycle were presented and discussed.Because of the steric hindrance on the C-3 of the indolence,the solute-solvent hydrogen bond interaction was dependent on the hydrogen bond donating ability of alcohols and steric effect of dyes.So the alcohol-solvent effecton the absorption,emission,and fluorscence quantum yield were somewhat different from the dyes without steric effect.The fluorescence decay of the dye obeyed biexpoential when the stronger hydrogen bond was formed,but the decay was monoexponenttial when the H-bond interaction weaker.