Wong, Natalie Gee Kwan, Berenbeim, Jacob and Dessent, Caroline Elizabeth Helen orcid.org/0000-0003-4944-0413 (2019) Direct Observation of Photochemical Free Radical Production from the Sunscreen 2‐Phenylbenzimidazole‐5‐Sulfonic Acid via Laser‐Interfaced Mass Spectrometry. Chemphotochem. ISSN 2367-0932
Abstract
The common sunscreen molecule 2‐phenylbenzimidazole‐5‐sulfonic acid (PBSA) is studied in its gas‐phase deprotonated form ([PBSA‐H]−) for the first time as an important step in achieving a better understanding of its behavior as a photosensitizer. UV laser‐interfaced mass spectrometry is employed, revealing that [PBSA‐H]− photofragments into three ionic products (m/z 208, 193, and 80) with distinctive wavelength‐dependent production profiles. Both the m/z 208 and 80 channels produce associated neutral free radical species. Collision‐induced dissociation is performed on [PBSA‐H]−, showing that its hot ground‐state dissociates only into m/z 193 (statistical fragment). Therefore, the m/z 208 and 80 fragments which are produced strongly through the UVA/UVB are characterized as non‐statistical photofragments associated with non‐ergodic excited‐state decay. Our observation of non‐statistical photofragments reveal that [PBSA‐H]− is not behaving as a model sunscreen molecule. Further, our results indicate that the T1 state, associated with photosensitization, decays with direct free radical production.
Metadata
Authors/Creators: |
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Copyright, Publisher and Additional Information: | Uploaded with permission of the publisher/copyright holder. Further copying may not be permitted; contact the publisher for details | ||||
Keywords: | Free radicals, LASER SPECTROSCOPY, Photolysis, Photosensitizer, Sunscreen Molecules | ||||
Dates: |
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Institution: | The University of York | ||||
Academic Units: | The University of York > Faculty of Sciences (York) > Chemistry (York) | ||||
Funding Information: |
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Depositing User: | Pure (York) | ||||
Date Deposited: | 28 Aug 2019 10:50 | ||||
Last Modified: | 04 Feb 2024 01:01 | ||||
Published Version: | https://doi.org/10.1002/cptc.201900149 | ||||
Status: | Published online | ||||
Refereed: | Yes | ||||
Identification Number: | https://doi.org/10.1002/cptc.201900149 |
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