Ultrafast excited state dynamics of fucoxanthin: excitation energy dependent intramolecular charge transfer dynamics

2011 ◽  
Vol 13 (22) ◽  
pp. 10762 ◽  
Author(s):  
Daisuke Kosumi ◽  
Toshiyuki Kusumoto ◽  
Ritsuko Fujii ◽  
Mitsuru Sugisaki ◽  
Yoshiro Iinuma ◽  
...  
2016 ◽  
Vol 18 (11) ◽  
pp. 7661-7671 ◽  
Author(s):  
Rajib Ghosh ◽  
Amitabha Nandi ◽  
Dipak K. Palit

Solvent sensitive excited state dynamics of DNBP is explored. In polar solvents, the ultrafast barrierless TICT process is the major relaxation pathway, whereas, in nonpolar solvents the excited state undergoes the PICT process, followed by efficient intersystem crossing to the triplet state.


2021 ◽  
Author(s):  
Qinying Pan ◽  
Mohamed Abdellah ◽  
Yuehan Cao ◽  
Yang Liu ◽  
Weihua Lin ◽  
...  

Abstract Rhenium(I)-carbonyl-diimine complexes are promising photocatalysts for CO2 reduction. Covalent organic frameworks (COFs) can be perfect sensitizers to enhance the reduction activities. Here we investigated the excited state dynamics of COF (TpBpy) with 2,2'-bipyridine incorporating Re(CO)5Cl (Re-TpBpy) to rationalize the underlying mechanism. The time-dependent DFT calculation first clarified excited state structure of the hybrid catalyst. The studies from transient visible and infrared spectroscopies revealed the excitation energy-dependent photo-induced charge transfer pathways in Re-TpBpy. Under low energy excitation, the electrons at the LUMO level are quickly injected from Bpy into ReI center (1–2 ps) followed by backward recombination (13 ps). Under high energy excitation, the hot-electrons are first injected into the higher unoccupied level of ReI center (1–2 ps) and then slowly relax back to the HOMO in COF (24 ps). There also remains long-lived free electrons in the COF moiety. This explained the excitation energy-dependent CO2 reduction performance in our system.


2019 ◽  
Vol 21 (31) ◽  
pp. 17323-17331 ◽  
Author(s):  
Xinmiao Niu ◽  
Prabhat Gautam ◽  
Zhuoran Kuang ◽  
Craig P. Yu ◽  
Yuanyuan Guo ◽  
...  

The solvation-dependent excited state dynamics of two push–pull fluorophores with donor–π–acceptor (D–π–A) structures were investigated using steady-state and ultrafast transient absorption (TA) spectroscopy, backed by theoretical calculations.


2021 ◽  
Author(s):  
Young Mo Sung ◽  
Eun Suk Kwon ◽  
Yusuke Makida Maruyama ◽  
Youngsik Shin ◽  
Soo-Ghang Ihn ◽  
...  

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.


Author(s):  
Weidong Qiu ◽  
Xinyi Cai ◽  
Mengke Li ◽  
Liangying Wang ◽  
Yanmei He ◽  
...  

Dynamic adjustment of emission behaviours by controlling the extent of twisted intramolecular charge transfer character in excited state.


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