Femtosecond Excited-State Dynamics of 4-Nitrophenyl Pyrrolidinemethanol: Evidence of Twisted Intramolecular Charge Transfer and Intersystem Crossing Involving the Nitro Group

2011 ◽  
Vol 115 (30) ◽  
pp. 8335-8343 ◽  
Author(s):  
Shahnawaz Rafiq ◽  
Rajeev Yadav ◽  
Pratik Sen
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Nitro Group ◽  
Intramolecular Charge Transfer ◽  
Intersystem Crossing ◽  
Twisted Intramolecular Charge Transfer ◽  
Excited State Dynamics

Solvent sensitive intramolecular charge transfer dynamics in the excited states of 4-N,N-dimethylamino-4′-nitrobiphenyl

2016 ◽  
Vol 18 (11) ◽  
pp. 7661-7671 ◽  
Author(s):  
Rajib Ghosh ◽  
Amitabha Nandi ◽  
Dipak K. Palit
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Triplet State ◽  
Excited States ◽  
Intramolecular Charge Transfer ◽  
Intersystem Crossing ◽  
Polar Solvents ◽  
Excited State Dynamics ◽  
Nonpolar Solvents ◽  
Charge Transfer Dynamics

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.

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.

Dynamic adjustment of emission from both singlets and triplets: the role of excited state conformation relaxation and charge transfer in phenothiazine derivates

2021 ◽  
Author(s):  
Weidong Qiu ◽  
Xinyi Cai ◽  
Mengke Li ◽  
Liangying Wang ◽  
Yanmei He ◽  
...  
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Intramolecular Charge Transfer ◽  
Dynamic Adjustment ◽  
Twisted Intramolecular Charge Transfer

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

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 ◽  
...  
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Excitation Energy ◽  
Intramolecular Charge Transfer ◽  
Excited State Dynamics ◽  
Charge Transfer Dynamics ◽  
Energy Dependent

Improving the fluorescence brightness of distyryl Bodipys by inhibiting the twisted intramolecular charge transfer excited state

2021 ◽  
Vol 57 (76) ◽  
pp. 9744-9747
Author(s):  
Xin Lv ◽  
Taihe Han ◽  
Yi Wu ◽  
Boran Zhang ◽  
Wei Guo
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Quaternary Ammonium ◽  
Intramolecular Charge Transfer ◽  
Twisted Intramolecular Charge Transfer

The fluorescence brightness of distyryl Bodipys was substantially improved by employing sulfone- and quaternary ammonium-modified piperidines as auxochromes instead of conventional dialkylamino auxochromes.

Intramolecular fluorescence quenching in aminocoumarines. Identification of an excited state with full charge separation

1985 ◽  
Vol 63 (7) ◽  
pp. 1649-1653 ◽  
Author(s):  
Wolfgang Rettig ◽  
André Klock
Keyword(s):  
Dipole Moment ◽  
Excited State ◽  
Charge Transfer ◽  
Fluorescence Quenching ◽  
Charge Separation ◽  
Intramolecular Charge Transfer ◽  
Stokes Shift ◽  
Twisted Intramolecular Charge Transfer ◽  
Full Charge

The fluorescence of 6-aminocoumarine (A6C) is very weak and anomalously redshifted as compared to its 7-substituted analogues 4-methyl-7-aminocoumarine (A7C) and 4-methyl-7-diethylaminocoumarine (DEA7C). The solvatochromic redshift in homologous alcohols is much stronger for A6C, pointing to an increased dipole moment of the emitting state. A twisted intramolecular charge transfer (TICT) state with full charge separation is made responsible for this emission. This is rationalized by molecules-in-molecules calculations. The strong Stokes shift in n-hexane and in ethanol glass at 77 K suggests that A6C emits from a TICT state even under these conditions.

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