scholarly journals Excited-State Intramolecular Proton Transfer: A Short Introductory Review

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1475
Author(s):  
Hem C. Joshi ◽  
Liudmil Antonov
Keyword(s):  
Excited State ◽  
Proton Transfer ◽  
Wavelength Dependence ◽  
Short Review ◽  
Intramolecular Proton Transfer ◽  
Excitation Wavelength ◽  
Double Proton Transfer ◽  
Geometrical Factors ◽  
Excitation Wavelength Dependence ◽  
Critical Aspects

In this short review, we attempt to unfold various aspects of excited-state intramolecular proton transfer (ESIPT) from the studies that are available up to date. Since Weller’s discovery of ESIPT in salicylic acid (SA) and its derivative methyl salicylate (MS), numerous studies have emerged on the topic and it has become an attractive field of research because of its manifold applications. Here, we discuss some critical aspects of ESIPT and tautomerization from the mechanistic viewpoint. We address excitation wavelength dependence, anti-Kasha ESIPT, fast and slow ESIPT, reversibility and irreversibility of ESIPT, hydrogen bonding and geometrical factors, excited-state double proton transfer (ESDPT), concerted and stepwise ESDPT.

Competitive excited-state single or double proton transfer mechanisms for bis-2,5-(2-benzoxazolyl)-hydroquinone and its derivatives

2015 ◽  
Vol 17 (18) ◽  
pp. 11990-11999 ◽  
Author(s):  
Jinfeng Zhao ◽  
Junsheng Chen ◽  
Jianyong Liu ◽  
Mark R. Hoffmann
Keyword(s):  
Density Functional Theory ◽  
Excited State ◽  
Proton Transfer ◽  
Density Functional ◽  
Intramolecular Proton Transfer ◽  
Time Dependent ◽  
Functional Theory ◽  
Double Proton Transfer ◽  
Transfer Mechanisms ◽  
Dependent Density

The excited state intramolecular proton transfer (ESIPT) mechanism of HBO, BBHQ and DHBO have been investigated using time-dependent density functional theory (TDDFT).

scholarly journals Theoretical Investigation of Excited-State Intramolecular Double-Proton Transfer Mechanism of Substituent Modified 1, 3-Bis (2-pyridylimino)-4,7-dihydroxyisoindole in Dichloromethane Solution

2021 ◽  
pp. 1-12
Author(s):  
Xiumin Liu ◽  
Heyao Yuan ◽  
Yuxi Wang ◽  
Yaping Tao ◽  
Yi Wang ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Excited State ◽  
Proton Transfer ◽  
Density Functional ◽  
Photophysical Properties ◽  
Substituent Effects ◽  
Intramolecular Proton Transfer ◽  
Hydrogen Bond Formation ◽  
Dichloromethane Solution ◽  
Double Proton Transfer

In this paper, density functional theory (DFT) and time-dependent DFT (TDDFT) methods were used to investigate substituent effects and excited-state intramolecular double-proton transfer (ESIDPT) in 1, 3-bis (2-pyridylimino)-4, 7-dihydroxyisoindole (BPI–OH) and its derivatives. The results of a systematic study of the substituent effects of electron-withdrawing groups (F, Cl and Br) on the adjacent sites of the benzene ring were used to regulate the photophysical properties of the molecules and the dynamics of the proton-transfer process. Geometric structure comparisons and infrared (IR) spectroscopic analysis confirmed that strengthening of the intramolecular hydrogen bond in the first excited state (S1) facilitated proton transfer. Functional analysis of the reduced density gradient confirmed these conclusions. Double-proton transfer in BPI–OH is considered to occur in two steps, i.e., BPI–OH (N) [Formula: see text] BPI–OH (T1) [Formula: see text] BPI–OH (T2), in the ground state (S0) and the S1 state. The potential-energy curves (PECs) for two-step proton transfer were scanned for both the S0 and S1 states to clarify the mechanisms and pathways of proton transfer. The stepwise path in which two protons are consecutively transferred has a low energy barrier and is more rational and favorable. This study shows that the presence or absence of coordinating groups, and the type of coordinating group, affect the hydrogen-bond strength. A coordinating group enhances hydrogen-bond formation, i.e., it promotes excited-state intramolecular proton transfer (ESIPT).

Sign in / Sign up

Export Citation Format

Share Document