title: Photoinduced electron transfer of N-[(3- and 4-diarylamino)phenyl]-1,8-naphthalimide dyads: orbital-orthogonal approach in a short-linked D-A system.
abstract: The photoinduced electron transfer of a series of meta- and para-linked triphenylamine-naphthalimide dyads, N-{3- and 4-[bis(4-R-substituted phenyl)amino]phenyl}-1,8-naphthalimide, 1m,p (R = H), 2m,p (R = Me), 3m,p (R = OMe), and 4m,p (R = NMe2) was investigated in toluene and DMF. The singlet charge-transfer (CT) states were observed in all cases. The decay rates were found to be faster in DMF (tau = 6.5 ps to 100 ps) than those in toluene (tau = 190 ps to 7 ns). The long-lived triplet CT states were observed in toluene for 3 (ca. 10% contribution, tau = 670 ns for 3m, 240 ns for 3p). No long-lived species were detected in DMF. The decay rates were somewhat faster in the para-isomers than in the meta-isomers in most cases. The photolysis of 5 (p-phenylene extended analogue of 3, R = OMe) gave a singlet CT state and a locally excited triplet state on the naphthalimide chromophore.
authors.affiliation: Department of Chemistry, Graduate School of Science, Osaka City University, Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan.
authors.forename: Seiichiro
authors.initials: S
authors.lastname: Takahashi
authors.forename: Koichi
authors.initials: K
authors.lastname: Nozaki
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Kozaki
authors.forename: Shuichi
authors.initials: S
authors.lastname: Suzuki
authors.forename: Kazutoshi
authors.initials: K
authors.lastname: Keyaki
authors.forename: Akio
authors.initials: A
authors.lastname: Ichimura
authors.forename: Toshio
authors.initials: T
authors.lastname: Matsushita
authors.forename: Keiji
authors.initials: K
authors.lastname: Okada