Phototransformations of Neutral Red dye in aqueous solutions in the presence of cucurbit[7]uril

Photophysical properties and photochemical transformations of Neutral Red (NR) dye in water in the presence of cucurbit[7]uril (CB7) were studied by absorption, fluorescence, and laser kinetic spectroscopies. Phototransformations of NR involve the triplet state of the dye and the production of NR radical cations and radical anions. The formation of inclusion complexes NR@CB7 was detected. The quantum yield of fluorescence and the efficiency of intersystem crossing to the triplet state increase in the presence of CB7.