Selenium Blue-α and -β: turning on the fluorescence of a pyrenyl fluorophore via oxidative cleavage of the Se–C bond by reactive oxygen species

Rapid oxidation of nonfluorescent pyrenyl-CH2SeAr (Ar = o-nitrophenyl) by hypochlorite yielded pyrenyl-CH2Cl and pyrenyl-CH2OH and turns on blue fluorescence, while slow oxidation of pyrenyl-CH2SeAr with excess H2O2 leads to pyrenyl-CHO which emits a bluish-green fluorescence. The homolog, pyrenyl-CH2CH2SeAr′ (Ar′ = o-nitrophenyl) reacts slower with H2O2 and ClO− giving the same product, vinyl pyrene.