1
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Mandal S, Srinivasan V. Rationalizing the Unexpected Sensitivity in Excited State Lifetimes of Adenine to Tautomerization by Nonadiabatic Molecular Dynamics. J Phys Chem B 2022; 126:7077-7087. [PMID: 36083211 DOI: 10.1021/acs.jpcb.2c03178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The remarkable photostability of canonical nucleobases makes them ideal building blocks for DNA and RNA. Even minor structural changes are expected to lead to drastic alteration of their subpicosecond excited state lifetimes. However, it is interesting to note that while the 9H- and 7H-amino tautomers of adenine possess drastically different lifetimes, 9H- and 7H-keto guanine possess similar excited state lifetimes. With an aim to explain this unexpected difference in sensitivity of lifetimes to tautomerization, we have investigated the excited state relaxation mechanism of UV-excited adenine and guanine tautomers using surface hopping based nonadiabatic molecular dynamics. We find that internal conversion in both guanine tautomers is almost barrierless while both adenine tautomers encounter significant barriers before they can deactivate. Moreover, the major deactivation channel (C2-puckering) in 9H-amino adenine is overall more efficient than the one (C6-puckering) in the 7H-amino form. We trace this difference to the frequent rotation of the amino group which disrupts its conjugation with the heterocyclic ring thereby reducing the strength of nonadiabatic coupling and, hence, delaying internal conversion.
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Affiliation(s)
- Satyajit Mandal
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal 462 066, India
| | - Varadharajan Srinivasan
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal 462 066, India
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2
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Fan J, Finazzi L, Jan Buma W. Elucidating the photoprotective properties of natural UV screening agents: ZEKE-PFI spectroscopy of methyl sinapate. Phys Chem Chem Phys 2022; 24:3984-3993. [PMID: 35099484 DOI: 10.1039/d1cp05958k] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
As a prominent derivative of a natural sunscreen, methyl sinapate is an ideal candidate to provide fundamental insight into strategies on how to come to a rational design of artificial sunscreen filters with improved photoprotective properties. Here, static and time-resolved Zero Kinetic Energy-Pulsed Field Ionization (ZEKE-PFI) photoelectron spectroscopy has been used to study the spectroscopy and decay pathways of its electronically excited states. We find that different conformers are subject to distinct structural changes upon electronic excitation, and trace the structural changes that occur upon excitation back to the character of the LUMO. Ionization efficiency spectra in combination with pump-probe ZEKE-PFI spectra are consistent with the conclusion that the long-lived electronically excited state observed in the decay of the lowest excited singlet state is the lowest excited triplet state. Concurrently with providing information on the electronically excited states, the studies allow for a detailed characterization of the spectroscopic properties of the ground state of the radical ion, which is important in the context of the use of cinnamates in nature as antioxidants. Our studies determine the adiabatic ionization energies of the syn/cis, anti/cis and anti/trans conformers as 60 291.1 ± 0.5, 60 366.9 ± 0.5 and 60 503.9 ± 1.0 cm-1, respectively, and provide accurate vibrational fequencies of low-frequency modes of the molecular ion in its electronic ground state. Finally, the studies emphasize the important role of vibrational and electronic autoionization processes that start to dominate the ionization dynamics in non-rigid molecules of the present size.
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Affiliation(s)
- Jiayun Fan
- Van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands.
| | - Laura Finazzi
- Van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands.
| | - Wybren Jan Buma
- Van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands. .,Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7c, 6525 ED Nijmegen, The Netherlands
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3
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Nomoto A, Inai N, Yanai T, Okuno Y. Substituent and Solvent Effects on the Photoisomerization of Cinnamate Derivatives: An XMS-CASPT2 Study. J Phys Chem A 2022; 126:497-505. [PMID: 35067053 DOI: 10.1021/acs.jpca.1c08504] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cinnamate derivatives show a variety of photo-induced reactions. Among them is trans-cis photoisomerization, which may involve the nonradiative decay (NRD) process. The extended multistate complete active space second-order perturbation (XMS-CASPT2) method was used in this study as a suitable theory for treating multireference electronic nature, which was frequently manifested in the photoisomerization process. The minimum energy paths of the trans-cis photoisomerization process of cinnamate derivatives were determined, and the activation energies were estimated using the resulting intrinsic reaction coordinate (IRC) paths. Natural orbital analysis revealed that the transition state's (TS) electronic structure is zwitterionic-like, elucidating the solvent and substituent effect on the energy barrier of photoisomerization paths. Furthermore, it was found that the charge on the pyramidalized carbon atom at the TS structure was strongly correlated with the activation energy barrier for the cinnamate derivatives. Thus, it seemingly provided a physical picture of the photoisomerization of cinnamates and was a good descriptor potentially applicable to molecular design for controlling the rate constant of the photoisomerization reaction.
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Affiliation(s)
- Atsuro Nomoto
- Analysis Technology Center, FUJIFILM Corporation, 210 Nakanuma, Minamiashigara, Kanagawa 250-0193, Japan
| | - Naoto Inai
- Department of Chemistry, Graduate School of Science, Nagoya University, Furocho, Chikusa, Nagoya, Aichi 464-8601, Japan
| | - Takeshi Yanai
- Department of Chemistry, Graduate School of Science, Nagoya University, Furocho, Chikusa, Nagoya, Aichi 464-8601, Japan.,Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Furocho, Chikusa, Nagoya, Aichi 464-8601, Japan
| | - Yukihiro Okuno
- Analysis Technology Center, FUJIFILM Corporation, 210 Nakanuma, Minamiashigara, Kanagawa 250-0193, Japan
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4
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Abiola TT, Rioux B, Toldo JM, Alarcan J, Woolley JM, Turner MAP, Coxon DJL, Telles do Casal M, Peyrot C, Mention MM, Buma WJ, Ashfold MNR, Braeuning A, Barbatti M, Stavros VG, Allais F. Towards developing novel and sustainable molecular light-to-heat converters. Chem Sci 2021; 12:15239-15252. [PMID: 34976344 PMCID: PMC8634993 DOI: 10.1039/d1sc05077j] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 10/18/2021] [Indexed: 12/18/2022] Open
Abstract
Light-to-heat conversion materials generate great interest due to their widespread applications, notable exemplars being solar energy harvesting and photoprotection. Another more recently identified potential application for such materials is in molecular heaters for agriculture, whose function is to protect crops from extreme cold weather and extend both the growing season and the geographic areas capable of supporting growth, all of which could help reduce food security challenges. To address this demand, a new series of phenolic-based barbituric absorbers of ultraviolet (UV) radiation has been designed and synthesised in a sustainable manner. The photophysics of these molecules has been studied in solution using femtosecond transient electronic and vibrational absorption spectroscopies, allied with computational simulations and their potential toxicity assessed by in silico studies. Following photoexcitation to the lowest singlet excited state, these barbituric absorbers repopulate the electronic ground state with high fidelity on an ultrafast time scale (within a few picoseconds). The energy relaxation pathway includes a twisted intramolecular charge-transfer state as the system evolves out of the Franck–Condon region, internal conversion to the ground electronic state, and subsequent vibrational cooling. These barbituric absorbers display promising light-to-heat conversion capabilities, are predicted to be non-toxic, and demand further study within neighbouring application-based fields. The synthesis and photophysical properties of phenolic barbiturics are reported. These molecules convert absorbed ultraviolet light to heat with high fidelity and may be suitable for inclusion in foliar sprays to boost crop protection and production.![]()
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Affiliation(s)
- Temitope T Abiola
- Department of Chemistry, University of Warwick Gibbet Hill Road Coventry CV4 7AL UK
| | - Benjamin Rioux
- URD Agro-Biotechnologies (ABI), CEBB, AgroParisTech 51110 Pomacle France
| | | | - Jimmy Alarcan
- Department of Food Safety, German Federal Institute for Risk Assessment Max-Dohrn-Str. 8-10 10589 Berlin Germany
| | - Jack M Woolley
- Department of Chemistry, University of Warwick Gibbet Hill Road Coventry CV4 7AL UK
| | - Matthew A P Turner
- Department of Chemistry, University of Warwick Gibbet Hill Road Coventry CV4 7AL UK .,Department of Physics, University of Warwick Gibbet Hill Road Coventry CV4 7AL UK
| | - Daniel J L Coxon
- Department of Chemistry, University of Warwick Gibbet Hill Road Coventry CV4 7AL UK .,Department of Physics, University of Warwick Gibbet Hill Road Coventry CV4 7AL UK.,EPSRC Centre for Doctoral Training in Diamond Science and Technology UK
| | | | - Cédric Peyrot
- URD Agro-Biotechnologies (ABI), CEBB, AgroParisTech 51110 Pomacle France
| | - Matthieu M Mention
- URD Agro-Biotechnologies (ABI), CEBB, AgroParisTech 51110 Pomacle France
| | - Wybren J Buma
- Van 't Hoff Institute for Molecular Sciences, University of Amsterdam Amsterdam The Netherlands.,Institute for Molecules and Materials, FELIX Laboratory, Radboud University 6525 ED Nijmegen The Netherlands
| | - Michael N R Ashfold
- School of Chemistry, University of Bristol Cantock's Close Bristol BS8 1TS UK
| | - Albert Braeuning
- Department of Food Safety, German Federal Institute for Risk Assessment Max-Dohrn-Str. 8-10 10589 Berlin Germany
| | - Mario Barbatti
- Aix Marseille Université, CNRS, ICR Marseille France .,Institut Universitaire de France 75231 Paris France
| | - Vasilios G Stavros
- Department of Chemistry, University of Warwick Gibbet Hill Road Coventry CV4 7AL UK
| | - Florent Allais
- URD Agro-Biotechnologies (ABI), CEBB, AgroParisTech 51110 Pomacle France
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5
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Toldo JM, do Casal MT, Barbatti M. Mechanistic Aspects of the Photophysics of UVA Filters Based on Meldrum Derivatives. J Phys Chem A 2021; 125:5499-5508. [PMID: 34151555 DOI: 10.1021/acs.jpca.1c03315] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Skin photoprotection against UVA radiation is crucial, but it is hindered by the sparsity of approved commercial UVA filters. Sinapoyl malate (SM) derivatives are promising candidates for a new class of UVA filters. They have been previously identified as an efficient photoprotective sunscreen in plants due to their fast nonradiative energy dissipation. Combining experimental and computational results, in our previous letter (J. Phys. Chem. Lett. 2021, 12, 337-344) we showed that coumaryl Meldrum (CMe) and sinapoyl Meldrum (SMe) are outstanding candidates for UVA filters in sunscreen formulations. Here, we deliver a comprehensive computational characterization of the excited-state dynamics of these molecules. Using reaction pathways and excited-state dynamics simulations, we could elucidate the photodeactivation mechanism of these molecules. Upon photoexcitation, they follow a two-step logistic decay. First, an ultrafast and efficient relaxation stabilizes the excited state alongside a 90° twisting around the allylic double bond, giving rise to a minimum with a twisted intramolecular excited-state (TICT) character. From this minimum, internal conversion to the ground state occurs after overcoming a 0.2 eV barrier. Minor differences in the nonradiative decay and fluorescence of CMe and SMe are associated with an additional minimum present only in the latter.
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Affiliation(s)
- Josene M Toldo
- Aix Marseille Université, CNRS, ICR, Av. Esc. Normandie-Niemen BJ5-D22, Marseille 13397, France
| | - Mariana T do Casal
- Aix Marseille Université, CNRS, ICR, Av. Esc. Normandie-Niemen BJ5-D22, Marseille 13397, France
| | - Mario Barbatti
- Aix Marseille Université, CNRS, ICR, Av. Esc. Normandie-Niemen BJ5-D22, Marseille 13397, France
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6
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Non-adiabatic Dynamics Mechanism in Excited State of Novel UV Protective Sunscreen in Rice: Conical Intersection Promotes Internal Conversion. J CLUST SCI 2021. [DOI: 10.1007/s10876-020-01819-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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7
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Kinoshita SN, Harabuchi Y, Inokuchi Y, Maeda S, Ehara M, Yamazaki K, Ebata T. Substitution effect on the nonradiative decay and trans → cis photoisomerization route: a guideline to develop efficient cinnamate-based sunscreens. Phys Chem Chem Phys 2021; 23:834-845. [PMID: 33284297 DOI: 10.1039/d0cp04402d] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Cinnamate derivatives are very useful as UV protectors in nature and as sunscreen reagents in daily life. They convert harmful UV energy to thermal energy through effective nonradiative decay (NRD) including trans → cis photoisomerization. However, the mechanism is not simple because different photoisomeirzation routes have been observed for different substituted cinnamates. Here, we theoretically examined the substitution effects at the phenyl ring of methylcinnamate (MC), a non-substituted cinnamate, on the electronic structure and the NRD route involving trans → cis isomerization based on time-dependent density functional theory. A systematic reaction pathway search using the single-component artificial force-induced reaction method shows that the very efficient photoisomerization route of MC can be essentially described as "1ππ* (trans) → 1nπ* → T1 (3ππ*) → S0 (trans or cis)". We found that for efficient 1ππ* (trans) → 1nπ* internal conversion (IC), MC should have the substituent at the appropriate position of the phenyl ring to stabilize the highest occupied π orbital. Substitution at the para position of MC slightly lowers the 1ππ* state energy and photoisomerization occurs via a slightly less efficient "1ππ* (trans) → 3nπ* → T1 (3ππ*) → S0 (trans or cis)" pathway. Substitution at the meta or ortho positions of MC significantly lowers the 1ππ* state energy so that the energy barrier of IC (1ππ* → 1nπ*) becomes very high. This substitution leads to a much longer 1ππ* state lifetime than that of MC and para-substituted MC, and a change in the dominant photoisomerization route to "1ππ* (trans) → C[double bond, length as m-dash]C bond twisting on 1ππ* → S0 (trans or cis)". As a whole, the "1ππ* → 1nπ*" IC observed in MC is the most important initial step for the rapid change of UV energy to thermal energy. We also found that the stabilization of the π orbital (i) minimizes the energy gap between 1ππ* and 1nπ* at the 1ππ* minimum and (ii) makes the 0-0 level of 1ππ* higher than 1nπ* as observed in MC. These MC-like relationships between the 1ππ* and 1nπ* energies should be ideal to maximize the "1ππ* → 1nπ*" IC rate constant according to Marcus theory.
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Affiliation(s)
- Shin-Nosuke Kinoshita
- Department of Chemistry, Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan.
| | - Yu Harabuchi
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan and Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, Sapporo 001-0021, Japan
| | - Yoshiya Inokuchi
- Department of Chemistry, Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan.
| | - Satoshi Maeda
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan and Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, Sapporo 001-0021, Japan
| | - Masahiro Ehara
- SOKENDAI, the Graduate University for Advanced Studies, Myodaiji, Okazaki 444-8585, Japan and Institute for Molecular Science and Research Center for Computational Science, 38, Myodaiji, Okazaki 444-8585, Japan
| | - Kaoru Yamazaki
- Institute for Materials Research, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai, 980-8577, Japan.
| | - Takayuki Ebata
- Department of Chemistry, Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan.
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8
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Sombutsuwan P, Jirattisakul A, Nakornsadet A, Akepratumchai S, Chumsantea S, Pojjanapornpun S, Lilitchan S, Krisnangkura K, Aryusuk K. A Simple and Efficient Method for Synthesis and Extraction of Ethyl Ferulate from γ-Oryzanol. J Oleo Sci 2021; 70:757-767. [PMID: 34078757 DOI: 10.5650/jos.ess20180] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Ethyl ferulate (EF) is a ferulic acid (FA) derivative with high commercial value. It is not found naturally and is mostly synthesized from FA via esterification with ethanol. The present work aimed to synthesize the EF from γ-oryzanol, a natural antioxidant from rice bran oil via acid-catalyzed transethylation at refluxing temperature of ethanol. The reaction was optimized by central composite design (CCD) under response surface methodology. Based on the CCD, the optimum condition for the synthesis of EF from 0.50 g of γ-oryzanol was as follows: γ-oryzanol to ethanol ratio of 0.50:2 (g/mL), 12.30% (v/v) H2SO4, and a reaction time of 9.37 h; these conditions correspond to a maximum EF yield of 87.11%. Moreover, the optimized transethylation condition was further validated using 12.50 g of γ-oryzanol. At the end of the reaction time, distilled water was added as antisolvent to selectively crystallize the co-products, phytosterol and unreacted γ-oryzanol, by adjusting the ethanol concentration to 49.95% (v/v). The recovery yield of 83.60% with a purity of 98% of EF was achieved. In addition, the DPPH and ABTS assays showed similar antioxidant activities between the prepared and commercial EF.
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Affiliation(s)
- Piraporn Sombutsuwan
- Division of Biochemical Technology, School of Bioresources and Technology, King Mongkut's University of Technology Thonburi
| | - Apiwat Jirattisakul
- Division of Biochemical Technology, School of Bioresources and Technology, King Mongkut's University of Technology Thonburi
| | - Akkaradech Nakornsadet
- Division of Biochemical Technology, School of Bioresources and Technology, King Mongkut's University of Technology Thonburi
| | - Saengchai Akepratumchai
- Division of Biotechnology, School of Bioresources and Technology, King Mongkut's University of Technology Thonburi
| | - Salisa Chumsantea
- Division of Biochemical Technology, School of Bioresources and Technology, King Mongkut's University of Technology Thonburi
| | - Siriluck Pojjanapornpun
- Pilot Plant Development and Training Institute (PDTI), King Mongkut's University of Technology, Thonburi (KMUTT)
| | | | - Kanit Krisnangkura
- Division of Biochemical Technology, School of Bioresources and Technology, King Mongkut's University of Technology Thonburi
| | - Kornkanok Aryusuk
- Division of Biochemical Technology, School of Bioresources and Technology, King Mongkut's University of Technology Thonburi
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9
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Fan J, Roeterdink W, Buma WJ. Excited-state dynamics of isolated and (micro)solvated methyl sinapate: the bright and shady sides of a natural sunscreen. Mol Phys 2020. [DOI: 10.1080/00268976.2020.1825850] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Jiayun Fan
- Van ‘t Hoff Institute for Molecular Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | - Wim Roeterdink
- Van ‘t Hoff Institute for Molecular Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | - Wybren Jan Buma
- Van ‘t Hoff Institute for Molecular Sciences, University of Amsterdam, Amsterdam, The Netherlands
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Nijmegen, The Netherlands
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10
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Baker LA, Staniforth M, Flourat AL, Allais F, Stavros VG. Conservation of ultrafast photoprotective mechanisms with increasing molecular complexity in sinapoyl malate derivatives. Chemphyschem 2020; 21:2006-2011. [PMID: 32638475 PMCID: PMC7586465 DOI: 10.1002/cphc.202000429] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 06/24/2020] [Indexed: 11/09/2022]
Abstract
Sinapoyl malate is a natural plant sunscreen molecule which protects leaves from harmful ultraviolet radiation. Here, the ultrafast dynamics of three sinapoyl malate derivatives, sinapoyl L-dimethyl malate, sinapoyl L-diethyl malate and sinapoyl L-di-t-butyl malate, have been studied using transient electronic absorption spectroscopy, in a dioxane and methanol solvent environment to investigate how well preserved these dynamics remain with increasing molecular complexity. In all cases it was found that, upon photoexcitation, deactivation occurs via a trans-cis isomerisation pathway within ∼20-30 ps. This cis-photoproduct, formed during photodeactivation, is stable and longed-lived for all molecules in both solvents. The incredible levels of conservation of the isomerisation pathway with increased molecular complexity demonstrate the efficacy of these molecules as ultraviolet photoprotectors, even in strongly perturbing solvents. As such, we suggest these molecules might be well-suited for augmentations to further improve their photoprotective efficacy or chemical compatibility with other components of sunscreen mixtures, whilst conserving their underlying photodynamic properties.
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Affiliation(s)
- Lewis A. Baker
- Department of ChemistryUniversity of WarwickGibbet Hill RoadCoventryCV4 7ALUnited Kingdom
- Faculty of Engineering and Physical SciencesUniversity of Surrey388 Stag HillGuildfordGU2 7XHUnited Kingdom
| | - Michael Staniforth
- Department of ChemistryUniversity of WarwickGibbet Hill RoadCoventryCV4 7ALUnited Kingdom
| | - Amandine L. Flourat
- URD Agro-Biotechnologies Industrielles (ABI), CEBB, AgroParisTech51110PomacleFrance
| | - Florent Allais
- URD Agro-Biotechnologies Industrielles (ABI), CEBB, AgroParisTech51110PomacleFrance
| | - Vasilios G. Stavros
- Department of ChemistryUniversity of WarwickGibbet Hill RoadCoventryCV4 7ALUnited Kingdom
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11
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Iida Y, Kinoshita SN, Kenjo S, Muramatsu S, Inokuchi Y, Zhu C, Ebata T. Electronic States and Nonradiative Decay of Cold Gas-Phase Cinnamic Acid Derivatives Studied by Laser Spectroscopy with a Laser-Ablation Technique. J Phys Chem A 2020; 124:5580-5589. [PMID: 32551660 DOI: 10.1021/acs.jpca.0c03646] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
We performed UV spectroscopy for p-coumaric acid (pCA), ferulic acid (FA), and caffeic acid (CafA) under jet-cooled gas-phase conditions by using a laser-ablation source. These molecules showed the S1(1ππ*)-S0 absorption in the 31 500-33 500 cm-1 region. Both pCA and FA exhibited sharp vibronic bands, while CafA showed only a broad feature. The decay time profile of the 1ππ* state was measured by picosecond pump-probe spectroscopy, and the transient state produced through the nonradiative decay (NRD) from 1ππ* and its time profile were measured by nanosecond UV-deep UV pump-probe spectroscopy. The transient state was observed for pCA and FA and assigned to the T1 state, and we concluded that the NRD process of 1ππ* is S1(1ππ*) → 1nπ* → T1(3ππ*), similar to those of methyl cinnamate and para-substituted cinnamates such as p-hydroxy and p-methoxy methyl cinnamate. On the other hand, the transient T1 state was not detected in CafA, and its NRD route is suggested to be S1(1ππ*) → 1πσ* → H atom elimination, similar to those of phenol and catechol. The effect of a hydrogen bond on the electronic state and NRD process was investigated, and it was found that the H-bonding lowers the 1ππ* energy and suppresses the NRD process for all the species.
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Affiliation(s)
- Yuji Iida
- Department of Chemistry, Graduate School of Science, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526, Japan
| | - Shin-Nosuke Kinoshita
- Department of Chemistry, Graduate School of Science, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526, Japan
| | - Seiya Kenjo
- Department of Chemistry, Graduate School of Science, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526, Japan
| | - Satoru Muramatsu
- Department of Chemistry, Graduate School of Science, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526, Japan
| | - Yoshiya Inokuchi
- Department of Chemistry, Graduate School of Science, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526, Japan
| | - Chaoyuan Zhu
- Department of Applied Chemistry and Institute for Molecular Science, National Chiao Tung University, Hsinchu 30010, Taiwan.,Center for Emergent Functional Matter Science, National Chiao Tung University, Hsinchu 30010, Taiwan
| | - Takayuki Ebata
- Department of Chemistry, Graduate School of Science, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526, Japan.,Department of Applied Chemistry and Institute for Molecular Science, National Chiao Tung University, Hsinchu 30010, Taiwan
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12
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Shi Y, Zhao X, Wang C, Wang Y, Zhang S, Li P, Feng X, Jin B, Yuan M, Cui S, Sun Y, Zhang B, Sun S, Jin X, Wang H, Zhao G. Ultrafast Nonadiabatic Photoisomerization Dynamics Mechanism for the UV Photoprotection of Stilbenoids in Grape Skin. Chem Asian J 2020; 15:1478-1483. [PMID: 32196972 DOI: 10.1002/asia.202000219] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 03/18/2020] [Indexed: 12/12/2022]
Abstract
Natural UV photoprotection plays a vital role in physiological protection. It has been reported that UVC radiation can make resveratrol (RSV) and piceatannol (PIC) accumulate in grape skin. In this work, we demonstrated that RSV and PIC could significantly absorb UVA and UVB, and confirmed their satisfactory photostability. Furthermore, we clarified the UV photoprotection mechanism of typical stilbenoids of RSV and PIC for the first time by using combined femtosecond transient absorption (FTA) spectroscopy and time-dependent density functional theory (TD-DFT) calculations. RSV and PIC can be photoexcited to the excited state after UVA and UVB absorption. Subsequently, the photoisomerized RSV and PIC quickly relax to the ground state via nonadiabatic transition from the S1 state at a conical intersection (CI) position between potential energy surfaces (PESs) of S1 and S0 states. This ultrafast trans-cis photoisomerization will take place within a few tens of picoseconds. As a result, the UV energy absorbed by RSV and PIC could be dissipated by an ultrafast nonadiabatic photoisomerization process.
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Affiliation(s)
- Yanan Shi
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences National Demonstration Center for Experimental Chemistry & Chemical engineering Education National Virtual Simulation Experimental Teaching Center for Chemistry & Chemical Engineering Education Department of Chemistry, School of Science Tianjin University, Tianjin, 300354, P. R. China
| | - Xiaoying Zhao
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences National Demonstration Center for Experimental Chemistry & Chemical engineering Education National Virtual Simulation Experimental Teaching Center for Chemistry & Chemical Engineering Education Department of Chemistry, School of Science Tianjin University, Tianjin, 300354, P. R. China
| | - Chao Wang
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences National Demonstration Center for Experimental Chemistry & Chemical engineering Education National Virtual Simulation Experimental Teaching Center for Chemistry & Chemical Engineering Education Department of Chemistry, School of Science Tianjin University, Tianjin, 300354, P. R. China
| | - Ye Wang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Song Zhang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Peng Li
- Institute of Molecular Sciences and Engineering, Shandong University, Qingdao, 266235, P. R. China
| | - Xia Feng
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences National Demonstration Center for Experimental Chemistry & Chemical engineering Education National Virtual Simulation Experimental Teaching Center for Chemistry & Chemical Engineering Education Department of Chemistry, School of Science Tianjin University, Tianjin, 300354, P. R. China
| | - Bing Jin
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Minghu Yuan
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Shen Cui
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences National Demonstration Center for Experimental Chemistry & Chemical engineering Education National Virtual Simulation Experimental Teaching Center for Chemistry & Chemical Engineering Education Department of Chemistry, School of Science Tianjin University, Tianjin, 300354, P. R. China
| | - Yan Sun
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences National Demonstration Center for Experimental Chemistry & Chemical engineering Education National Virtual Simulation Experimental Teaching Center for Chemistry & Chemical Engineering Education Department of Chemistry, School of Science Tianjin University, Tianjin, 300354, P. R. China
| | - Bing Zhang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Shuqing Sun
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences National Demonstration Center for Experimental Chemistry & Chemical engineering Education National Virtual Simulation Experimental Teaching Center for Chemistry & Chemical Engineering Education Department of Chemistry, School of Science Tianjin University, Tianjin, 300354, P. R. China
| | - Xiaoning Jin
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences National Demonstration Center for Experimental Chemistry & Chemical engineering Education National Virtual Simulation Experimental Teaching Center for Chemistry & Chemical Engineering Education Department of Chemistry, School of Science Tianjin University, Tianjin, 300354, P. R. China
| | - Haiyuan Wang
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences National Demonstration Center for Experimental Chemistry & Chemical engineering Education National Virtual Simulation Experimental Teaching Center for Chemistry & Chemical Engineering Education Department of Chemistry, School of Science Tianjin University, Tianjin, 300354, P. R. China
| | - Guangjiu Zhao
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences National Demonstration Center for Experimental Chemistry & Chemical engineering Education National Virtual Simulation Experimental Teaching Center for Chemistry & Chemical Engineering Education Department of Chemistry, School of Science Tianjin University, Tianjin, 300354, P. R. China
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13
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Berenbeim JA, Wong NGK, Cockett MCR, Berden G, Oomens J, Rijs AM, Dessent CEH. Unravelling the Keto-Enol Tautomer Dependent Photochemistry and Degradation Pathways of the Protonated UVA Filter Avobenzone. J Phys Chem A 2020; 124:2919-2930. [PMID: 32208697 PMCID: PMC7168606 DOI: 10.1021/acs.jpca.0c01295] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
![]()
Avobenzone (AB) is
a widely used UVA filter known to undergo irreversible
photodegradation. Here, we investigate the detailed pathways by which
AB photodegrades by applying UV laser-interfaced mass spectrometry
to protonated AB ions. Gas-phase infrared multiple-photon dissociation
(IRMPD) spectra obtained with the free electron laser for infrared
experiments, FELIX, (600–1800 cm–1) are also
presented to confirm the geometric structures. The UV gas-phase absorption
spectrum (2.5–5 eV) of protonated AB contains bands that correspond
to selective excitation of either the enol or diketo forms, allowing
us to probe the resulting, tautomer-dependent photochemistry. Numerous
photofragments (i.e., photodegradants) are directly identified for
the first time, with m/z 135 and
161 dominating, and m/z 146 and
177 also appearing prominently. Analysis of the production spectra
of these photofragments reveals that that strong enol to keto photoisomerism
is occurring, and that protonation significantly disrupts the stability
of the enol (UVA active) tautomer. Close comparison of fragment ion
yields with the TD-DFT-calculated absorption spectra give detailed
information on the location and identity of the dissociative excited
state surfaces, and thus provide new insight into the photodegradation
pathways of avobenzone, and photoisomerization of the wider class
of β-diketone containing molecules.
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Affiliation(s)
- Jacob A Berenbeim
- Department of Chemistry, University of York, Heslington, York, YO10 5DD, U.K
| | - Natalie G K Wong
- Department of Chemistry, University of York, Heslington, York, YO10 5DD, U.K
| | - Martin C R Cockett
- Department of Chemistry, University of York, Heslington, York, YO10 5DD, U.K
| | - Giel Berden
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7, Nijmegen, 6500 HC, The Netherlands
| | - Jos Oomens
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7, Nijmegen, 6500 HC, The Netherlands
| | - Anouk M Rijs
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7, Nijmegen, 6500 HC, The Netherlands
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14
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Bacardit A, Cartoixà X. Revisiting the Role of Irradiance in the Determination of Sunscreens' Sun Protection Factor. J Phys Chem Lett 2020; 11:1209-1214. [PMID: 32075378 DOI: 10.1021/acs.jpclett.9b03437] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The efficacy of a sunscreen tends to be associated with its sun protection factor (SPF) value, a figure determined in a test that relies on the independence of the SPF value to both UV radiation dose and irradiance. We probe these assumptions when photoinduced product degradation is present, and we estimate that the theoretical limit for their validity is when the sunfilter active molecule relaxation time is faster than ∼10 ns. While such threshold relaxation time should be compatible with the expected ultrafast relaxation mechanisms of sunfilter molecules (picoseconds), recent research on sunfilter photodynamics has identified the existence of much longer-lived molecular states. Such long lifetimes could compromise sunscreen performance and make the SPF value very different in natural sun irradiance conditions than in the solar simulated conditions typically used in SPF determination tests.
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Affiliation(s)
| | - Xavier Cartoixà
- Departament d'Enginyeria Electrònica , Universitat Autònoma de Barcelona , 08193 Cerdanyola del Vallès , Spain
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15
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Muramatsu S, Nakayama S, Kinoshita SN, Onitsuka Y, Kohguchi H, Inokuchi Y, Zhu C, Ebata T. Electronic State and Photophysics of 2-Ethylhexyl-4-methoxycinnamate as UV-B Sunscreen under Jet-Cooled Condition. J Phys Chem A 2020; 124:1272-1278. [PMID: 31992045 DOI: 10.1021/acs.jpca.9b11893] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The title compound, 2-ethylhexyl-4-methoxycinnamate (2EH4MC), is known as a typical ingredient of sunscreen cosmetics that effectively converts the absorbed UV-B light to thermal energy. This energy conversion process includes the nonradiative decay (NRD): trans-cis isomerization and finally going back to the original structure with a release of thermal energy. In this study, we performed UV spectroscopy for jet-cooled 2EH4MC to investigate the electronic/geometrical structures as well as the NRD mechanism. Laser-induced-fluorescence (LIF) spectroscopy gave the well-resolved vibronic structure of the S1-S0 transition; UV-UV hole-burning (HB) spectroscopy and density functional theory (DFT) calculations revealed the presence of syn and anti isomers, where the methoxy (-OCH3) groups orient in opposite directions to each other. Picosecond UV-UV pump-probe spectroscopy revealed the NRD process from the excited singlet (S1 (1ππ*)) state occurs at a rate constant of ∼1010-1011 s-1, attributed to internal conversion (IC) to the 1nπ* state. Nanosecond UV-deep UV (DUV) pump-probe spectroscopy identified a transient triplet (T1 (3ππ*)) state, whose energy (from S0) and lifetime are 18 400 cm-1 and 20 ns, respectively. These results demonstrate that the photoisomerization of 2EH4MC includes multistep internal conversions and intersystem crossings, described as "S1 (trans, 1ππ*) → 1nπ* → T1 (3ππ*) → S0 (cis)".
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Affiliation(s)
- Satoru Muramatsu
- Department of Chemistry, Graduate School of Science , Hiroshima University , 1-3-1 Kagamiyama , Higashi-Hiroshima-shi , Hiroshima 739-8526 , Japan
| | - Shingo Nakayama
- Department of Chemistry, Graduate School of Science , Hiroshima University , 1-3-1 Kagamiyama , Higashi-Hiroshima-shi , Hiroshima 739-8526 , Japan
| | - Shin-Nosuke Kinoshita
- Department of Chemistry, Graduate School of Science , Hiroshima University , 1-3-1 Kagamiyama , Higashi-Hiroshima-shi , Hiroshima 739-8526 , Japan
| | - Yuuki Onitsuka
- Department of Chemistry, Graduate School of Science , Hiroshima University , 1-3-1 Kagamiyama , Higashi-Hiroshima-shi , Hiroshima 739-8526 , Japan
| | - Hiroshi Kohguchi
- Department of Chemistry, Graduate School of Science , Hiroshima University , 1-3-1 Kagamiyama , Higashi-Hiroshima-shi , Hiroshima 739-8526 , Japan
| | - Yoshiya Inokuchi
- Department of Chemistry, Graduate School of Science , Hiroshima University , 1-3-1 Kagamiyama , Higashi-Hiroshima-shi , Hiroshima 739-8526 , Japan
| | - Chaoyuan Zhu
- Department of Applied Chemistry and Institute for Molecular Science , National Chiao Tung University , Hsinchu 30010 , Taiwan.,Center for Emergent Functional Matter Science , National Chiao Tung University , Hsinchu 30010 , Taiwan
| | - Takayuki Ebata
- Department of Chemistry, Graduate School of Science , Hiroshima University , 1-3-1 Kagamiyama , Higashi-Hiroshima-shi , Hiroshima 739-8526 , Japan.,Department of Applied Chemistry and Institute for Molecular Science , National Chiao Tung University , Hsinchu 30010 , Taiwan
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16
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Horbury MD, Holt EL, Mouterde LMM, Balaguer P, Cebrián J, Blasco L, Allais F, Stavros VG. Towards symmetry driven and nature inspired UV filter design. Nat Commun 2019; 10:4748. [PMID: 31628301 PMCID: PMC6802189 DOI: 10.1038/s41467-019-12719-z] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 09/26/2019] [Indexed: 12/13/2022] Open
Abstract
In plants, sinapate esters offer crucial protection from the deleterious effects of ultraviolet radiation exposure. These esters are a promising foundation for designing UV filters, particularly for the UVA region (400 – 315 nm), where adequate photoprotection is currently lacking. Whilst sinapate esters are highly photostable due to a cis-trans (and vice versa) photoisomerization, the cis-isomer can display increased genotoxicity; an alarming concern for current cinnamate ester-based human sunscreens. To eliminate this potentiality, here we synthesize a sinapate ester with equivalent cis- and trans-isomers. We investigate its photostability through innovative ultrafast spectroscopy on a skin mimic, thus modelling the as close to true environment of sunscreen formulas. These studies are complemented by assessing endocrine disruption activity and antioxidant potential. We contest, from our results, that symmetrically functionalized sinapate esters may show exceptional promise as nature-inspired UV filters in next generation sunscreen formulations. Sinapate esters are promising nature-inspired sunscreen and antioxidant agents but their photoisomerization may lead to ineffective or harmful species. Here the authors propose a symmetric ester with indistinguishable trans and cis isomers and prove its effectiveness by optical spectroscopies on a skin mimic.
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Affiliation(s)
- Michael D Horbury
- Department of Chemistry, University of Warwick, Gibbet Hill, Coventry, CV4 7AL, UK. .,School of Electronic and Electrical Engineering, University of Leeds, Leeds, LS2 9JT, UK.
| | - Emily L Holt
- Department of Chemistry, University of Warwick, Gibbet Hill, Coventry, CV4 7AL, UK.,Molecular Analytical Science Centre for Doctoral Training, Senate House, University of Warwick, Coventry, CV4 7AL, UK
| | - Louis M M Mouterde
- URD Agro-Biotechnologies Industrielles (ABI), CEBB, AgroParisTech, 51110, Pomacle, France
| | | | - Juan Cebrián
- Lubrizol Advanced Materials, C/Isaac Peral 17-Pol. Industrial Cami Ral, 08850, Gava, Spain
| | - Laurent Blasco
- Lubrizol Advanced Materials, C/Isaac Peral 17-Pol. Industrial Cami Ral, 08850, Gava, Spain
| | - Florent Allais
- URD Agro-Biotechnologies Industrielles (ABI), CEBB, AgroParisTech, 51110, Pomacle, France
| | - Vasilios G Stavros
- Department of Chemistry, University of Warwick, Gibbet Hill, Coventry, CV4 7AL, UK.
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17
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Jhang WR, Lai HY, Lin YC, Lee C, Lee SH, Lee YY, Ni CK, Tseng CM. Triplet vs πσ* state mediated N–H dissociation of aniline. J Chem Phys 2019; 151:141101. [DOI: 10.1063/1.5121350] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Affiliation(s)
- Wan Ru Jhang
- Department of Applied Chemistry, National Chiao Tung University, Hsinchu 30010, Taiwan
| | - Hsin Ying Lai
- Department of Applied Chemistry, National Chiao Tung University, Hsinchu 30010, Taiwan
| | - Yen-Cheng Lin
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - Chin Lee
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - Shih-Huang Lee
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - Yin-Yu Lee
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - Chi-Kung Ni
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
- Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Chien-Ming Tseng
- Department of Applied Chemistry, National Chiao Tung University, Hsinchu 30010, Taiwan
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18
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Holt EL, Stavros VG. Applications of ultrafast spectroscopy to sunscreen development, from first principles to complex mixtures. INT REV PHYS CHEM 2019. [DOI: 10.1080/0144235x.2019.1663062] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Emily L. Holt
- Molecular Analytical Science Centre for Doctoral Training, Senate House, University of Warwick, Coventry, UK
- Department of Chemistry, University of Warwick, Coventry, UK
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19
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Kinoshita SN, Inokuchi Y, Onitsuka Y, Kohguchi H, Akai N, Shiraogawa T, Ehara M, Yamazaki K, Harabuchi Y, Maeda S, Ebata T. The direct observation of the doorway 1nπ* state of methylcinnamate and hydrogen-bonding effects on the photochemistry of cinnamate-based sunscreens. Phys Chem Chem Phys 2019; 21:19755-19763. [PMID: 31259349 DOI: 10.1039/c9cp02914a] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The electronic states and photochemistry including nonradiative decay (NRD) and trans(E) → cis(Z) isomerization of methylcinnamate (MC) and its hydrogen-bonded complex with methanol have been investigated under jet-cooled conditions. S1(1nπ*) and S2(1ππ*) are directly observed in MC. This is the first direct observation of S1(1nπ*) in cinnamate derivatives. Surprisingly, the order of the energies between the nπ* and ππ* states is opposite to substituted cinnamates. TD-DFT and SAC-CI calculations support the observed result and show that the substitution to the benzene ring largely lowers the 1ππ* energy while the effect on 1nπ* is rather small. The S2(ππ*) state lifetime of MC is determined to be equal to or shorter than 10 ps, and the production of the transient T1 state is observed. The T1(ππ*) state is calculated to have a structure in which propenyl C[double bond, length as m-dash]C is twisted by 90°, suggesting the trans → cis isomerization proceeds via T1. The production of the cis isomer is confirmed by low-temperature matrix-isolated FTIR spectroscopy. The effect of H-bonding is examined for the MC-methanol complex. The S2 lifetime of MC-methanol is determined to be 180 ps, indicating that the H-bonding to the C[double bond, length as m-dash]O group largely prohibits the 1ππ* → 1nπ* internal conversion. This lifetime elongation in the methanol complex also describes well a higher fluorescence quantum yield of MC in methanol solution than in cyclohexane, while such a solvent dependence is not observed in para-substituted MC. Determination of the photochemical reaction pathways of MC and MC-methanol will help us to design photofunctional cinnamate derivatives.
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Affiliation(s)
- Shin-Nosuke Kinoshita
- Department of Chemistry, Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan.
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20
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Wong NGK, Berenbeim JA, Hawkridge M, Matthews E, Dessent CEH. Mapping the intrinsic absorption properties and photodegradation pathways of the protonated and deprotonated forms of the sunscreen oxybenzone. Phys Chem Chem Phys 2019; 21:14311-14321. [PMID: 30680382 DOI: 10.1039/c8cp06794e] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Sunscreens provide vital protection against the photodamaging effects of UV radiation, however, many fundamental questions remain about the detailed mechanisms by which they dissipate UV energy. One such issue is the extent to which the pH environment of an organic sunscreen molecule alters its effectiveness, both in terms of ability to absorb UV radiation, and also its potential to photodegrade. Here, we use gas-phase laser photodissociation spectroscopy for the first time to measure the intrinsic UVA-UVC absorption spectra and associated photodegradation products of protonated and deprotonated oxybenzone, away from the complications of bulk mixtures. Our results reveal that protonation state has a dramatic effect on the absorption and photodissociation properties of this sunscreen. While the UV absorption profile of oxybenzone is only modestly affected by protonation across the range from 400-216 nm, deprotonated oxybenzone displays a significantly modified absorption spectrum, with very low photoabsorption between 370-330 nm. Protonated oxybenzone primarily photofragments by rupture of the bonds on either side of the central carbonyl group, producing cationic fragments with m/z 151 and 105. Additional lower mass photofragments (e.g. m/z 95 and 77) are also observed. The production spectra for the photofragments from protonated oxybenzone fall into two distinct categories, which we discuss in the context of different excited state decay pathways. For deprotonated oxybenzone, the major photofragments observed are m/z 211 and 212, which are associated with the ejection of methane and the methyl free radical from the parent ion, respectively. Implications for the suitability of oxybenzone in its protonated and deprotonated forms as an optimum sunscreen molecule are discussed.
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Affiliation(s)
- Natalie G K Wong
- Department of Chemistry, University of York, Heslington, York YO10 5DD, UK.
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21
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Woolley JM, Peters JS, Turner MAP, Clarkson GJ, Horbury MD, Stavros VG. The role of symmetric functionalisation on photoisomerisation of a UV commercial chemical filter. Phys Chem Chem Phys 2019; 21:14350-14356. [DOI: 10.1039/c8cp06536e] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Photoisomerisation has been shown to be an efficient excited-state relaxation mechanism for a variety of nature-based and artificial-based molecular systems.
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22
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Kenjo S, Iida Y, Chaki N, Kinoshita SN, Inokuchi Y, Yamazaki K, Ebata T. Laser spectroscopic study on sinapic acid and its hydrated complex in a cold gas phase molecular beam. Chem Phys 2018. [DOI: 10.1016/j.chemphys.2018.07.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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23
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Kinoshita SN, Miyazaki Y, Sumida M, Onitsuka Y, Kohguchi H, Inokuchi Y, Akai N, Shiraogawa T, Ehara M, Yamazaki K, Harabuchi Y, Maeda S, Taketsugu T, Ebata T. Different photoisomerization routes found in the structural isomers of hydroxy methylcinnamate. Phys Chem Chem Phys 2018; 20:17583-17598. [PMID: 29693100 DOI: 10.1039/c8cp00414e] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
An experimental and theoretical study has been carried out to elucidate the nonradiative decay (NRD) and trans(E) → cis(Z) isomerization from the S1 (1ππ*) state of structural isomers of hydroxy methylcinnamate (HMC); ortho-, meta- and para-HMC (o-, m- and p-HMC). A low temperature matrix-isolation Fourier Transform Infrared (FTIR) spectroscopic study revealed that all the HMCs are cis-isomerized upon UV irradiation. A variety of laser spectroscopic methods have been utilized for jet-cooled gas phase molecules to investigate the vibronic structure and lifetimes of the S1 state, and to detect the transient state appearing in the NRD process. In p-HMC, the zero-point level of the S1 state decays as quickly as 9 ps. A transient electronic state reported by Tan et al. (Faraday Discuss. 2013, 163, 321-340) was reinvestigated by nanosecond UV-tunable deep UV pump-probe spectroscopy and was assigned to the T1 state. For m- and o-HMC, the lifetime at the zero-point energy level of S1 is 10 ns and 6 ns, respectively, but it becomes substantially shorter at an excess energy higher than 1000 cm-1 and 600 cm-1, respectively, indicating the onset of NRD. Different from p-HMC, no transient state (T1) was observed in m- nor o-HMC. These experimental results are interpreted with the aid of TDDFT calculations by considering the excited-state reaction pathways and the radiative/nonradiative rate constants. It is concluded that in p-HMC, the trans → cis isomerization proceeds via a [trans-S1 → 1nπ* → T1 → cis-S0] scheme. On the other hand, in o- and m-HMC, the isomerization proceeds via a [trans-S1 → twisting along the C[double bond, length as m-dash]C double bond by 90° on S1 → cis-S0] scheme. The calculated barrier height along the twisting coordinate agrees well with the observed onset of the NRD channel for both o- and m-HMC.
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Affiliation(s)
- Shin-Nosuke Kinoshita
- Department of Chemistry, Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan.
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24
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Baker LA, Staniforth M, Flourat AL, Allais F, Stavros VG. Gas-Solution Phase Transient Absorption Study of the Plant Sunscreen Derivative Methyl Sinapate. CHEMPHOTOCHEM 2018. [DOI: 10.1002/cptc.201800060] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Lewis A. Baker
- Department of Chemistry; University of Warwick; Gibbet Hill Road Coventry CV4 7AL United Kingdom
- Present address: Department of Science; George Abbot School; Woodruff Avenue Guildford, Surrey GU1 1XX United Kingdom
| | - Michael Staniforth
- Department of Chemistry; University of Warwick; Gibbet Hill Road Coventry CV4 7AL United Kingdom
| | - Amandine L. Flourat
- Chaire Agro-Biotechnologies Industrielles (ABI); AgroParisTech; CEBB 3 rue des Rouges Terres F-51110 Pomacle France
| | - Florent Allais
- Chaire Agro-Biotechnologies Industrielles (ABI); AgroParisTech; CEBB 3 rue des Rouges Terres F-51110 Pomacle France
| | - Vasilios G. Stavros
- Department of Chemistry; University of Warwick; Gibbet Hill Road Coventry CV4 7AL United Kingdom
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25
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Abstract
Despite the pivotal role of ultraviolet (UV) radiation in sustaining life on Earth, overexposure to this type of radiation can have catastrophic effects, such as skin cancer. Sunscreens, the most common form of artificial protection against such harmful effects, absorb UV radiation before it reaches vulnerable skin cells. Absorption of UV radiation prompts ultrafast molecular events in sunscreen molecules which, ideally, would allow for fast and safe dissipation of the excess energy. However, our knowledge of these mechanisms remains limited. In this article, we will review recent advances in the field of ultrafast photodynamics (light induced molecular processes occurring within femtoseconds, fs, 10-15 s to picoseconds, ps, 10-12 s) of sunscreens. We follow a bottom-up approach to common sunscreen active ingredients, analysing any emerging trends from the current literature on the subject. Moreover, we will identify the main questions that remain unanswered, pinpoint some of the main challenges and finally comment on the outlook of this exciting field of research.
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26
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Fang YG, Li CX, Chang XP, Cui G. Photophysics of a UV-B Filter 4-Methylbenzylidene Camphor: Intersystem Crossing Plays an Important Role. Chemphyschem 2018; 19:744-752. [PMID: 29288547 DOI: 10.1002/cphc.201701230] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 12/29/2017] [Indexed: 11/07/2022]
Abstract
4-Methylbenzylidene camphor (4MBC) is a frequently used ultraviolet (UV) filter in commercial sunscreens, which is experimentally found to undergo efficient intersystem crossing to triplet manifolds followed by predominant radiationless decay to the ground state. However, its photophysical mechanism is unclear. Herein, we have employed combined CASPT2 and CASSCF methods to study the spectroscopic properties, geometric and electronic structures, conical intersections and crossing points, and excited-state deactivation channels of 4MBC. We have found that the V(1 ππ*) state is populated with large probability in the Franck-Condon region. Starting from this state, there are two efficient nonradiative relaxation processes to populate the 3 ππ* state. In the first one, the V(1 ππ*) state decays to the V'(1 ππ*) state. The resultant V'(1 ππ*) state further jumps to the 1 nπ* state by internal conversion at the 1 ππ*/1 nπ* conical intersection. Then, the 1 nπ* state hops to the 3 ππ* state through an efficient 1 nπ*→3 ππ* intersystem crossing process. In the second one, the V(1 ππ*) state can diabatically relax along the photoisomerization reaction coordinate. In this process, a 1 ππ*/3 nπ* crossing point helps the 1 ππ* system decay to the 3 nπ* state, which further decays to the 3 ππ* state through internal conversion at the 3 nπ*/3 ππ* conical intersection. Once the 3 ππ* state is formed, a nearly barrierless relaxation path drives the 3 ππ* system to hop to the S0 state via the 3 ππ*/S0 crossing point. Our current work not only rationalizes recent experimental observations but also enriches our photophysical knowledge of UV filters.
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Affiliation(s)
- Ye-Guang Fang
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, 100875, China
| | - Chun-Xiang Li
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, 100875, China
| | - Xue-Ping Chang
- College of Chemistry and Chemical Engineering, Xinyang Normal University, Xinyang, 464000, China
| | - Ganglong Cui
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, 100875, China
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Rodrigues N, Cole-Filipiak N, Horbury M, Staniforth M, Karsili T, Peperstraete Y, Stavros V. Photophysics of the sunscreen ingredient menthyl anthranilate and its precursor methyl anthranilate: A bottom-up approach to photoprotection. J Photochem Photobiol A Chem 2018. [DOI: 10.1016/j.jphotochem.2017.11.042] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Horbury MD, Baker LA, Rodrigues ND, Quan WD, Stavros VG. Photoisomerization of ethyl ferulate: A solution phase transient absorption study. Chem Phys Lett 2017. [DOI: 10.1016/j.cplett.2017.02.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Rodrigues NDN, Staniforth M, Stavros VG. Photophysics of sunscreen molecules in the gas phase: a stepwise approach towards understanding and developing next-generation sunscreens. Proc Math Phys Eng Sci 2016; 472:20160677. [PMID: 27956888 PMCID: PMC5134319 DOI: 10.1098/rspa.2016.0677] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 10/24/2016] [Indexed: 12/22/2022] Open
Abstract
The relationship between exposure to ultraviolet (UV) radiation and skin cancer urges the need for extra photoprotection, which is presently provided by widespread commercially available sunscreen lotions. Apart from having a large absorption cross section in the UVA and UVB regions of the electromagnetic spectrum, the chemical absorbers in these photoprotective products should also be able to dissipate the excess energy in a safe way, i.e. without releasing photoproducts or inducing any further, harmful, photochemistry. While sunscreens are tested for both their photoprotective capability and dermatological compatibility, phenomena occurring at the molecular level upon absorption of UV radiation are largely overlooked. To date, there is only a limited amount of information regarding the photochemistry and photophysics of these sunscreen molecules. However, a thorough understanding of the intrinsic mechanisms by which popular sunscreen molecular constituents dissipate excess energy has the potential to aid in the design of more efficient, safer sunscreens. In this review, we explore the potential of using gas-phase frequency- and time-resolved spectroscopies in an effort to better understand the photoinduced excited-state dynamics, or photodynamics, of sunscreen molecules. Complementary computational studies are also briefly discussed. Finally, the future outlook of expanding these gas-phase studies into the solution phase is considered.
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Peperstraete Y, Staniforth M, Baker LA, Rodrigues NDN, Cole-Filipiak NC, Quan WD, Stavros VG. Bottom-up excited state dynamics of two cinnamate-based sunscreen filter molecules. Phys Chem Chem Phys 2016; 18:28140-28149. [DOI: 10.1039/c6cp05205c] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
We have used time-resolved pump–probe spectroscopy to explore E-MMC's and E-EHMC's excited state dynamics upon UV-B photoexcitation.
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