INTRAMOLECULAR EXCIMER FORMATION and MOLECULAR RECOGNITION OF MODIFIED CYCLODEXTRINS APPENDED BY TWO NAPHTHALENE RINGS*

The intramolecular excimer formation of 6A,6B‐, 6A,6C‐, 6A,6D‐, and 6A,6E‐bis(2‐naphthyl‐sulfonyl)‐γ‐cyclodextrins (1, 2, 3, and 4, respectively) and 6A.6B‐, 6A,6C‐, and 6A,6D‐bis(2‐naphthyl‐sulfonyl)‐β‐cyclodextrins (5, 6, and 7, respectively) has been studied in 10% ethylene glycol aqueous solution. The two naphthyl rings are co‐included in the γ‐cyclodextrin cavities of1–4, and marked excimer emission was observed for 2, 3, and 4. On the other hand, almost pure monomer emission was observed for 5, 6, and 7 due to inclusion of one of two naphthyl rings in the β‐cyclodextrin cavities. Compounds 2, 3, 6, and 7 showed remarkable guest‐induced enhancement in the excimer emission, and this property was used for detecting several organic compounds with remarkable molecular recognition.