Photoinduced intramolecular charge transfer precedence over Enol-Keto isomerization in a molecular system: Spectroscopic exploration

IF 3.3 3区物理与天体物理 Q2 OPTICS

Journal of Luminescence Pub Date : 2025-02-25 DOI:10.1016/j.jlumin.2025.121152

Souvik Santra, Atanu Panja, Indrani Das, Najnin Mandal, Rintu Mondal, Nikhil Guchhait

{"title":"Photoinduced intramolecular charge transfer precedence over Enol-Keto isomerization in a molecular system: Spectroscopic exploration","authors":"Souvik Santra, Atanu Panja, Indrani Das, Najnin Mandal, Rintu Mondal, Nikhil Guchhait","doi":"10.1016/j.jlumin.2025.121152","DOIUrl":null,"url":null,"abstract":"<div><div>In this article we report excited state properties of Methyl-4-(diphenylamino)-2-hydroxybenzoate (<strong>DPHB</strong>), a newly-designed synthetic molecule having both the intramolecular charge transfer (ICT) and excited state intramolecular proton transfer (ESIPT) sites. Competitive photoinduced processes in this molecular system have been extensively studied in different solvents with varying polarity, hydrogen bonding capability using steady state absorption and emission and time-resolved emission spectroscopy. Spectral comparison of <strong>DPHB</strong> with two other more or less similar synthetic compounds 4-(diphenylamino)-2-methoxybenzoate (<strong>DPMB</strong>) and methyl 4-(diphenylamino)benzoate (<strong>DPB</strong>), both with only charge transfer channel and with Methyl salicylate (<strong>MS</strong>) having only proton transfer channel supports preferential charge transfer over proton transfer (PT) reaction in <strong>DPHB</strong>. The molecule <strong>DPHB</strong> shows high energy emission from the locally excited state (∼400 nm) and solvent dependent Stokes shifted charge transfer emission (>450 nm) in polar aprotic solvents where ICT emission is slower (>6ns) than the emission from the locally excited state (<2ns). The dynamics of the excited state is comparatively faster in polar protic solvents due to solute-solvent H-bonding interaction. Structural calculation and theoretical PECs both along the donor twist coordinate and PT coordinate at Density Functional Theory (DFT) level also supports favourable charge transfer with low excited state energy barrier.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"281 ","pages":"Article 121152"},"PeriodicalIF":3.3000,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Luminescence","FirstCategoryId":"101","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0022231325000924","RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"OPTICS","Score":null,"Total":0}

引用次数: 0

Abstract

In this article we report excited state properties of Methyl-4-(diphenylamino)-2-hydroxybenzoate (DPHB), a newly-designed synthetic molecule having both the intramolecular charge transfer (ICT) and excited state intramolecular proton transfer (ESIPT) sites. Competitive photoinduced processes in this molecular system have been extensively studied in different solvents with varying polarity, hydrogen bonding capability using steady state absorption and emission and time-resolved emission spectroscopy. Spectral comparison of DPHB with two other more or less similar synthetic compounds 4-(diphenylamino)-2-methoxybenzoate (DPMB) and methyl 4-(diphenylamino)benzoate (DPB), both with only charge transfer channel and with Methyl salicylate (MS) having only proton transfer channel supports preferential charge transfer over proton transfer (PT) reaction in DPHB. The molecule DPHB shows high energy emission from the locally excited state (∼400 nm) and solvent dependent Stokes shifted charge transfer emission (>450 nm) in polar aprotic solvents where ICT emission is slower (>6ns) than the emission from the locally excited state (<2ns). The dynamics of the excited state is comparatively faster in polar protic solvents due to solute-solvent H-bonding interaction. Structural calculation and theoretical PECs both along the donor twist coordinate and PT coordinate at Density Functional Theory (DFT) level also supports favourable charge transfer with low excited state energy barrier.

Abstract Image

查看原文本刊更多论文

求助全文

约1分钟内获得全文求助全文

来源期刊

Journal of Luminescence 物理-光学

CiteScore

6.70

自引率

13.90%

发文量

850

审稿时长

3.8 months

期刊介绍： The purpose of the Journal of Luminescence is to provide a means of communication between scientists in different disciplines who share a common interest in the electronic excited states of molecular, ionic and covalent systems, whether crystalline, amorphous, or liquid. We invite original papers and reviews on such subjects as: exciton and polariton dynamics, dynamics of localized excited states, energy and charge transport in ordered and disordered systems, radiative and non-radiative recombination, relaxation processes, vibronic interactions in electronic excited states, photochemistry in condensed systems, excited state resonance, double resonance, spin dynamics, selective excitation spectroscopy, hole burning, coherent processes in excited states, (e.g. coherent optical transients, photon echoes, transient gratings), multiphoton processes, optical bistability, photochromism, and new techniques for the study of excited states. This list is not intended to be exhaustive. Papers in the traditional areas of optical spectroscopy (absorption, MCD, luminescence, Raman scattering) are welcome. Papers on applications (phosphors, scintillators, electro- and cathodo-luminescence, radiography, bioimaging, solar energy, energy conversion, etc.) are also welcome if they present results of scientific, rather than only technological interest. However, papers containing purely theoretical results, not related to phenomena in the excited states, as well as papers using luminescence spectroscopy to perform routine analytical chemistry or biochemistry procedures, are outside the scope of the journal. Some exceptions will be possible at the discretion of the editors.