ANILIDE LINKER GROUP AS A PARTICIPANT IN INTRAMOLECULAR ELECTRON-TRANSFER

The photochemical properties of derivatives of 10-methylacridinium ion that have been modified by substitution with anilide moieties (e.g., -C6H4NHCO-) at the 9-position have been examined. Intramolecular elect ron transfer involving the anilide group as electron donor and the acr idinium ring as electron acceptor was verified by observation of the q uenching of fluorescence associated with the local acridinium chromoph ore and by the recording of electron transfer phototransient spectra i n the picosecond time domain. The amidobiphenyl linkage was a superior electron donor and displayed rapid forward and reverse photoinduced e lectron transfer with rate constants for the latter reaching 5.2 x 10( 11) s(-1) (CH3CN solvent).