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Excited state intramolecular proton transfer reaction revisited: S1 state or general reversibility?

Paper ID Volume ID Publish Year Pages File Format Full-Text
27861 44047 2012 10 PDF Available
Title
Excited state intramolecular proton transfer reaction revisited: S1 state or general reversibility?
Abstract

The excited state intramolecular proton transfer (ESIPT) reaction reversibility was reexamined both experimentally and theoretically on the example of a series of 3-hydroxychromone (3HC) derivatives. The experimental reversibility criteria for the excited state adiabatic photoreactions based on dynamic quenching of two-banded 3HC fluorescence were re-deduced. Quenching experiments in the series of 3HC with the specially selected quencher, which does not absorb on the excitation wavelength, 2,4-dinitrotoluene, did not reveal the excited state reversibility in any of the examined dry aprotic solvents of different polarity. Quantum-chemical modeling including the excited state molecular geometry analysis, estimation of the ground and excited state H-bonds energies with the application of the “atoms in molecules” (AIM) approach and calculation of energetic profiles of the forward and back proton transfer reactions in the S0 and S1 states allows us to conclude there are no serious prerequisites for the excited state reversibility of the intramolecular proton transfer reaction.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► The problem of the S1-state reversibility of ESIPT is reconsidered ► The new and more stringent criterion based on collisional quenching for the experimental examination of ESIPT reversibility is deduced ► Quantum-chemical modeling reveals weakening of the intramolecular H-bond in the T* form: no driving force for the reversed ESIPT? ► Radiationless deactivation of the excited phototautomer T* is an important background of ESIPT-based ratiometric fluorescence detection.

Keywords
ESIPT; Reversible or irreversible adiabatic photochemical reaction; 3-Hydroxychromone; Fluorescence quenching; Quantum-chemical modeling; Atoms in molecules (AIM) approach; H-bond energy; Ground and excited state energetic profiles of the ESIPT reaction
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Publisher
Database: Elsevier - ScienceDirect
Journal: Journal of Photochemistry and Photobiology A: Chemistry - Volume 250, 15 December 2012, Pages 40–49
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us