Triplet state reactivity and long-lived room temperature phosphorescence of chalcones enabled by micelles

Cheap SDS micelles are used to facilitate long-lived room temperature phosphorescence and [2+2] photocycloadditions of chalcone by enabling excited-state aggregate formation. Within the micellar environment chalcone aggregation is promoted leading to stabilization of a planar geometry in the triplet state, resulting in long lived (19 μs) emission λ(max) = 700 nm under blue light irradiation. This long-lived triplet state is exploited in [2+2] cycloadditions with activated alkenes. The micelles effectively isolate the reactive species from molecular oxygen, thereby preventing undesired quenching of triplet states.