Photoinduced coupled twisted intramolecular charge transfer and excited-state proton transfer via intermolecular hydrogen bonding: A DFT/TD-DFT study

Jen

Phys. Chem. Chem. Phys.

et al. 2022

Section: Introductionmentioning

confidence: 99%

Intramolecular charge transfer of a push–pull chromophore with restricted internal rotation of an electron donor

Jen

Phys. Chem. Chem. Phys.

et al. 2022

“…The DFT/TDDFT methods are suitable to study the mechanism involving PT, ESIPT, and ICT process. − For instance, by using these calculation methods, our group has successfully proposed the mechanism for thiazolidinedione derivative in dimethylformamide solution that TICT could facilitate ESIPT initiated by intermolecular hydrogen-bond strengthening in the S 1 state . Zhao’s group clearly demonstrated that for N,N -dimethylanilino-1,3-diketone (DMADK) chromophore, the ESIPT and TICT process were coupled in the S 1 state rather than sequential ESIPT and TICT process, and these calculated results are consistent with those reported by Ciofini’s group …”

Section: Introductionmentioning

confidence: 99%

DFT/TDDFT Study on the Sensing Mechanism of a Fluorescent Probe for Hydrogen Sulfide: Excited State Intramolecular Proton Transfer Coupled Twisted Intramolecular Charge Transfer

Chu

2017

J. Phys. Chem. A

By using density functional theory (DFT) and time-dependent density functional theory (TDDFT) methods, the sensing mechanism of a fluorescent probe 2-(2-hydroxyphenyl) benzothiazole (HBT) derivative HBTPP-S for hydrogen sulfide has been thoroughly studied. The thiolysis reaction has a moderate reaction barrier of 18.40 kcal mol, which indicates that the hydrogen sulfide sensing process has a favorable response speed. Because of the nonradiative donor-excited photoinduced electron transfer (d-PET, fluorophore as the electron donor) from the excited HBTPP group to the electron-withdrawing 2,4-dinitrophenyl group, as well as the inhibition of the proton transfer (PT) and the excited state intramolecular proton transfer (ESIPT) process by 2,4-dinitrophenyl group, the probe HBTPP-S is essentially nonfluorescent. On the other hand, the added hydrogen sulfide induces the thiolysis of the 2,4-dinitrophenyl ether bond, and then the thiolysis product HBTPP comes into existence. The theoretically simulated potential energy surface demonstrates that without the electron-withdrawing 2,4-dinitrophenyl group, the thiolysis product HBTPP undergoes the excited state intramolecular proton transfer (ESIPT) coupled twisted intramolecular charge transfer (TICT) processes in the first excited state. The absence of the d-PET and the process mentioned above may explain the significant fluorescent turn-on response and large Stokes shift of the thiolysis product HBTPP.

Photoinduced hydrogen-bonding dynamics

Chu

2016

J Mol Model

Hydrogen bonding dynamics has received extensive research attention in recent years due to the significant advances in femtolaser spectroscopy experiments and quantum chemistry calculations. Usually, photoexcitation would cause changes in the hydrogen bonding formed through the interaction between hydrogen donor and acceptor molecules on their ground electronic states, and such transient strengthening or weakening of hydrogen bonding could be crucial for the photophysical transformations and the subsequent photochemical reactions that occurred on a time scale from tens of femtosecond to a few nanoseconds. In this article, we review the combined experimental and theoretical studies focusing on the ultrafast electronic and vibrational hydrogen bonding dynamics. Through these studies, new mechanisms and proposals and common rules have been put forward to advance our understanding of the hydrogen bondings dynamics in a variety of important photoinduced phenomena like photosynthesis, dual fluorescence emission, rotational reorientation, excited-state proton transfer and charge transfer processes, chemosensor fluorescence sensing, rearrangements of the hydrogen-bond network including forming and breaking hydrogen bond in water. Graphical Abstract We review the recent advances on exploring the photoinduced hydrogen bonding dynamics in solutions through a joint approach of laser spectroscopy and theoretical calculation. The reviewed studies have put forward a new mechanism, new proposal, and new rule for a variety of photoinduced phenomena such as photosynthesis, dual fluorescence emission, rotational reorientation, excited-state proton transfer and charge transfer, chemosensor fluorescence sensing, and rearrangements of the hydrogen-bond network in water.