title: Photoinduced intramolecular electron transfer in conjugated perylene bisimide-dithienothiophene systems: a comparative study of a small molecule and a polymer.
abstract: The solution photophysical properties of two conjugated dithienothiophene (DTT)-perylene bisimide (PBI) systemsa polymer, poly{[N,N'-bis(2-decyl-tetradecyl)-3,4,9,10-perylene diimide-1,7-diyl]-alt-(dithieno[3,2-b:2',3'-d]thiophene-2,6-diyl)}, and a small molecule, 1,7-bis(dithieno[3,2-b:2',3'-d]thiophene-2-yl)-N,N'-bis(2-decyl-tetradecyl)-3,4,9,10-perylene diimidein solution have been investigated. Strong quenching of the fluorescence of the PBI moiety was observed in both DTT-PBI systems, suggesting the possibility of an efficient intramolecular electron-transfer process. The kinetics of photoinduced electron transfer in the DTT-PBI polymer and monomer in solutions were explored by femtosecond time-resolved transient absorption spectra. It was found that both the rates of charge separation and charge recombination in the DTT-PBI polymer were approximately double those in the small molecule. This indicates that electronic coupling plays an important role in the electron-transfer process in a polymer system.
authors.affiliation: Beijing National Laboratory for Molecular Sciences (BNLMS) and Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China.
authors.forename: Jie
authors.initials: J
authors.lastname: Huang
authors.forename: Yishi
authors.initials: Y
authors.lastname: Wu
authors.forename: Hongbing
authors.initials: H
authors.lastname: Fu
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Zhan
authors.forename: Jiannian
authors.initials: J
authors.lastname: Yao
authors.forename: Stephen
authors.initials: S
authors.lastname: Barlow
authors.forename: Seth R
authors.initials: SR
authors.lastname: Marder