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603879 
Journal Article 
Intramolecular Excimer Formation and Photoinduced Electron-Transfer Process in Bis-1,8-Naphthalimide Dyads Depending on the Linker Length 
Dae Won, C; Mamoru, F; Akira, S; Tetsuro, M 
2008 
1 
Journal of Physical Chemistry A
ISSN: 1089-5639
EISSN: 1520-5215 
112 
31 
7208-7213 
The photophysical properties of bis-1,8-naphthalimide (NI−L−NI) dyads with different linkers ( L= −C 3H 6−, −C 4H 8−, −C 6H 12−, −C 8H 16−, and −C 9H 18−) as well as the reference NI derivative (NI−C 7H 15) were investigated in CH 3CN and H 2O/CH 3CN (v/v = 1:9). The normal fluorescence peak of 1NI*−L−NI was observed at 379 nm together with a broad emission at longer wavelength both in aprotic CH 3CN and in H 2O/CH 3CN, which is assigned to an excimer, 1(NI−L−NI)*. The excimer emission maximum was blue-shifted with increasing length of the linker. The photoinduced electron-transfer process of NI−L−NI was also investigated in both solvents by using nanosecond-laser flash photolysis. The T 1−T nabsorption band for 3NI*−L−NI was observed around 470 nm in both solvents. In H 2O/CH 3CN, NI−L−NI is solvated with H 2O in the ground state to exist as solvated NI−L−NI. In the excited triplet state, the NI radical anion (NI •−) was generated via the intramolecular quenching of 3NI*−L−NI by another NI moiety. The solvated NI •−−L−NI may undergo the proton abstraction process to give NI(H) •−L−NI, which can be confirmed by the transient absorption band at 410 nm. This band was not observed in pure aprotic CH 3CN. [ABSTRACT FROM AUTHOR] Copyright of Journal of Physical Chemistry A is the property of American Chemical Society and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts) 
CHARGE exchange; NAPHTHALENE; IMIDES; FLASH photolysis; FLUORESCENCE; CHEMICAL reactions; SOLVENTS