Substitution effects of CC triple bonds on the fluorescent properties of perylenes studied by emission and transient absorption measurements

Perylenes substituted with trimethylsilylethynyl, tert-butylethynyl and trimethylsilylbutadiynyl groups were prepared, and their photophysical and photochemical properties were investigated through measurements of fluorescence yields, lifetimes, and triplet–triplet absorption. Introduction of these groups caused little change in the rates of fluorescence, but decreased the fluorescence yields and substantially enhanced the rates of non-radiative processes. Observation of the triplet absorption was evident for the origin of the enhanced non-radiative process by the substitution with the triple bond(s).