Structural Changes Accompanying Intramolecular Electron Transfer:  Focus on Twisted Intramolecular Charge-Transfer States and Structures

2003 ◽  
Vol 103 (10) ◽  
pp. 3899-4032 ◽  
Author(s):  
Zbigniew R. Grabowski ◽  
Krystyna Rotkiewicz ◽  
Wolfgang Rettig
Keyword(s):  
Electron Transfer ◽  
Charge Transfer ◽  
Structural Changes ◽  
Intramolecular Charge Transfer ◽  
Intramolecular Electron Transfer ◽  
Twisted Intramolecular Charge Transfer

scholarly journals Recent advances in twisted intramolecular charge transfer (TICT) fluorescence and related phenomena in materials chemistry

2016 ◽  
Vol 4 (14) ◽  
pp. 2731-2743 ◽  
Author(s):  
Shunsuke Sasaki ◽  
Gregor P. C. Drummen ◽  
Gen-ichi Konishi
Keyword(s):  
Electron Transfer ◽  
Charge Transfer ◽  
Transfer Process ◽  
Intramolecular Charge Transfer ◽  
Materials Chemistry ◽  
Single Bond ◽  
Electron Transfer Process ◽  
Twisted Intramolecular Charge Transfer ◽  
Recent Advances ◽  
Donor And Acceptor

Twisted intramolecular charge transfer (TICT) is an electron transfer process that occurs upon photoexcitation in molecules that usually consist of a donor and acceptor part linked by a single bond.

Effect of bulky meso-substituents on photoinduced twisted intramolecular charge transfer processes in meso-diarylamino subporphyrins

2016 ◽  
Vol 20 (06) ◽  
pp. 663-669 ◽  
Author(s):  
Seung-Kyu Lee ◽  
Jun Oh Kim ◽  
Daiki Shimizu ◽  
Atsuhiro Osuka ◽  
Dongho Kim
Keyword(s):  
Charge Transfer ◽  
Intramolecular Charge Transfer ◽  
Solvent Polarity ◽  
Intramolecular Electron Transfer ◽  
Separation Processes ◽  
Time Resolved ◽  
Twisted Intramolecular Charge Transfer ◽  
Transfer Processes ◽  
Steady State Time ◽  
Photoexcited State

Photoexcited-state dynamics of meso-diarylamino subporphyrins 4–6 in cyclohexane, toluene, and acetonitrile have been studied by steady-state/time-resolved absorption and fluorescence experiments and quantum calculations. While 4 emits fluorescence from the locally excited state regardless of solvent polarity, the fluorescence of 5 and 6 are solvent-polarity dependent. The observed efficient fluorescent quenching of 5 and 6 has been ascribed to twisted intramolecular charge transfer (TICT), in which the two N–C[Formula: see text] bonds in 5 and the C[Formula: see text]–N bond in 6 are twisted to facilitate the intramolecular electron transfer. In 2-methyltetrahydrofuran (2-MeTHF), the fluorescence of 5 and 6 are both almost completely quenched at 297 K, but restored at 77 K (below the melting point of 2-MeTHF) because of the frozen molecular twisting. Furthermore, electrochemical studies also revealed the charge separation processes of 4–6 are thermally unfavorable in nonpolar toluene and cyclohexane unless their structures change contrary to the observed efficient fluorescence quenching. These observations support the TICT mechanism. In addition, the formation of TICT state is affected by steric effect as the size of the meso-substituents increases.

Influence of π-conjugation structural changes on intramolecular charge transfer and photoinduced electron transfer in donor–π–acceptor dyads

2017 ◽  
Vol 19 (1) ◽  
pp. 426-435 ◽  
Author(s):  
So-Yoen Kim ◽  
Yang-Jin Cho ◽  
Ah-Rang Lee ◽  
Ho-jin Son ◽  
Won-Sik Han ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Charge Transfer ◽  
Photoinduced Electron Transfer ◽  
Structural Changes ◽  
Intramolecular Charge Transfer ◽  
Selective Excitation ◽  
Electron Transfers ◽  
Acceptor Moiety

Unit electron transfers (PET or PHT) were observed dominantly in the dyads having severed/twisted linkers in the π-conjugation and their mechanisms are also affected by whether selective excitation of the donor or acceptor moiety occurs.

scholarly journals Controlling the Twisted Intramolecular Charge-Transfer Character of Pyrene Derivatives Through Solvent Polarity

2021 ◽  
Author(s):  
Young Mo Sung ◽  
Eun Suk Kwon ◽  
Yusuke Makida Maruyama ◽  
Youngsik Shin ◽  
Soo-Ghang Ihn ◽  
...  
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Structural Changes ◽  
Intramolecular Charge Transfer ◽  
Photophysical Properties ◽  
Critical Role ◽  
Solvent Polarity ◽  
Twisted Intramolecular Charge Transfer ◽  
Excited State Dynamics ◽  
Pyrene Derivatives

Abstract Intramolecular charge transfer (ICT) plays a critical role in determining the photophysical properties of organic molecules, including their luminescence efficiencies. Twisted intramolecular charge transfer (TICT) is a process in which structural change accompanies ICT. Despite significant research, the relationship between TICT and solvent polarity, and its effects on photophysical properties, have been rarely investigated. Herein, we used time-resolved spectroscopy to study TICT in pyrene derivatives that are promising blue organic light emitting diode (OLED) emitter candidates; these derivatives show strong solvent-dependent charge-transfer (CT) behavior. Slight structural changes that do not affect excited state dynamics were observed in nonpolar solvents, while polar solvents were found to affect excited state dynamics and CT characteristics. The TICT behavior of these pyrene derivatives could be modulated through structural modification. Our study provides valuable guidelines for the control of optical properties, including the luminescence efficiencies of OLED emitters that show TICT characteristics.

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