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Conformation of the Ester Group Governs the Photophysics of Highly Polarized Benzo[g]coumarins
[Image: see text] Photosensitizers that display “unusual” emission from upper electronically excited states offer possibilities for initiating higher-energy processes than what the governing Kasha’s rule postulates. Achieving conditions for dual fluorescence from multiple states of the same species...
Autores principales: | , , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
American Chemical Society
2023
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10369411/ https://www.ncbi.nlm.nih.gov/pubmed/37502148 http://dx.doi.org/10.1021/jacsau.3c00169 |
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author | Szychta, Kamil Koszarna, Beata Banasiewicz, Marzena Sobolewski, Andrzej O’Mari, Omar Clark, John A. Vullev, Valentine I. Barboza, Cristina A. Gryko, Daniel T. |
author_facet | Szychta, Kamil Koszarna, Beata Banasiewicz, Marzena Sobolewski, Andrzej O’Mari, Omar Clark, John A. Vullev, Valentine I. Barboza, Cristina A. Gryko, Daniel T. |
author_sort | Szychta, Kamil |
collection | PubMed |
description | [Image: see text] Photosensitizers that display “unusual” emission from upper electronically excited states offer possibilities for initiating higher-energy processes than what the governing Kasha’s rule postulates. Achieving conditions for dual fluorescence from multiple states of the same species requires molecular design and conditions that favorably tune the excited-state dynamics. Herein, we switch the position of the electron-donating NMe(2) group around the core of benzo[g]coumarins (BgCoum) and tune the electronic coupling and the charge-transfer character of the fluorescent excited states. For solvents with intermediate polarity, three of the four regioisomers exhibit fluorescence from two different excited states with bands that are well separated in the visible and the near-infrared spectral regions. Computational analysis, employing ab initio methods, reveals that the orientation of an ester on the pyrone ring produces two conformers responsible for the observed dual fluorescence. Studies with solid solvating media, which restricts the conformational degrees of freedom, concur with the computational findings. These results demonstrate how “seemingly inconsequential” auxiliary substituents, such as the esters on the pyrone coumarin rings, can have profound effects leading to “anti-Kasha” photophysical behavior important for molecular photonics, materials engineering, and solar-energy science. |
format | Online Article Text |
id | pubmed-10369411 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2023 |
publisher | American Chemical Society |
record_format | MEDLINE/PubMed |
spelling | pubmed-103694112023-07-27 Conformation of the Ester Group Governs the Photophysics of Highly Polarized Benzo[g]coumarins Szychta, Kamil Koszarna, Beata Banasiewicz, Marzena Sobolewski, Andrzej O’Mari, Omar Clark, John A. Vullev, Valentine I. Barboza, Cristina A. Gryko, Daniel T. JACS Au [Image: see text] Photosensitizers that display “unusual” emission from upper electronically excited states offer possibilities for initiating higher-energy processes than what the governing Kasha’s rule postulates. Achieving conditions for dual fluorescence from multiple states of the same species requires molecular design and conditions that favorably tune the excited-state dynamics. Herein, we switch the position of the electron-donating NMe(2) group around the core of benzo[g]coumarins (BgCoum) and tune the electronic coupling and the charge-transfer character of the fluorescent excited states. For solvents with intermediate polarity, three of the four regioisomers exhibit fluorescence from two different excited states with bands that are well separated in the visible and the near-infrared spectral regions. Computational analysis, employing ab initio methods, reveals that the orientation of an ester on the pyrone ring produces two conformers responsible for the observed dual fluorescence. Studies with solid solvating media, which restricts the conformational degrees of freedom, concur with the computational findings. These results demonstrate how “seemingly inconsequential” auxiliary substituents, such as the esters on the pyrone coumarin rings, can have profound effects leading to “anti-Kasha” photophysical behavior important for molecular photonics, materials engineering, and solar-energy science. American Chemical Society 2023-06-26 /pmc/articles/PMC10369411/ /pubmed/37502148 http://dx.doi.org/10.1021/jacsau.3c00169 Text en © 2023 The Authors. Published by American Chemical Society https://creativecommons.org/licenses/by/4.0/Permits the broadest form of re-use including for commercial purposes, provided that author attribution and integrity are maintained (https://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Szychta, Kamil Koszarna, Beata Banasiewicz, Marzena Sobolewski, Andrzej O’Mari, Omar Clark, John A. Vullev, Valentine I. Barboza, Cristina A. Gryko, Daniel T. Conformation of the Ester Group Governs the Photophysics of Highly Polarized Benzo[g]coumarins |
title | Conformation of the
Ester Group Governs the Photophysics
of Highly Polarized Benzo[g]coumarins |
title_full | Conformation of the
Ester Group Governs the Photophysics
of Highly Polarized Benzo[g]coumarins |
title_fullStr | Conformation of the
Ester Group Governs the Photophysics
of Highly Polarized Benzo[g]coumarins |
title_full_unstemmed | Conformation of the
Ester Group Governs the Photophysics
of Highly Polarized Benzo[g]coumarins |
title_short | Conformation of the
Ester Group Governs the Photophysics
of Highly Polarized Benzo[g]coumarins |
title_sort | conformation of the
ester group governs the photophysics
of highly polarized benzo[g]coumarins |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10369411/ https://www.ncbi.nlm.nih.gov/pubmed/37502148 http://dx.doi.org/10.1021/jacsau.3c00169 |
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