Tuning the donors to control the lifetimes of charge-separated states in triazine-based donor-acceptor systems

• Published in: Dyes and pigments 2017-01, Vol.136, p.404-415
• Main Authors: Lu, Ting, Sun, Haiya, Colley, Nathan D., Bridgmohan, Chelsea N., Liu, Dongzhi, Li, Wei, Hu, Wenping, Zhou, Xueqin, Wang, Tianyang, Wang, Lichang
• Format: Article
• Language: English
• Subjects: Charge-separated state; Donor-acceptor system; Driving force; Lifetime; Photoinduced electron transfer; Reorganization energy
• ISSN: 0143-7208; 1873-3743
• DOI: 10.1016/j.dyepig.2016.08.042

Six donor-acceptor systems with styrene based 9-phenyl carbazole, 4,4’-di(hydro, methyl, methoxy or octyloxy) triphenylamine and 4-methylphenyl indoline derivatives as donors, and s-triazine group as the acceptor were synthesized and characterized. The charge-separated states of these donor-acceptor systems were generated through the effective photoinduced electron transfers from excited donor modules to acceptor modules and had lifetimes ranging from 57 ns to 215 ns. These donor-acceptor systems are capable of fast charge separation, but have extremely slow charge recombination. The back electron transfer processes of these donor-acceptor systems occur in the inverted region of the Marcus curve. The driving forces of back electron transfer and the reorganization energies of electron transfer decrease in the order of 9-phenyl carbazole derivative, 4,4’-di(hydro, methyl, methoxy or octyloxy) triphenylamine derivative and 4-methylphenyl indoline derivative. These two factors work together to determine the different lifetimes of charge-separated states in these donor-acceptor systems. [Display omitted] •Six s-triazine based donor-acceptor systems were synthesized and characterized.•These donor-acceptor systems have different lifetimes of charge separated states.•The driving forces and reorganization energies of electron transfer determine the lifetimes.