1
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Huang G, Li J, Deng Z, Li J, Sun S, Xu L, Dang L, Li MD. Room-Temperature Stable Noncovalent Charge-Transfer Dianion Biradical to Produce Singlet Oxygen by Visible or Near-Infrared Light Photoexcitation. J Phys Chem Lett 2021; 12:4306-4312. [PMID: 33913708 DOI: 10.1021/acs.jpclett.1c00759] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Noncovalent interaction between small molecules can generate a charge-transfer (CT) state, achieving the effect of a conjugated large molecule as well as a transition-metal complex. Herein, we demonstrate a room-temperature stable dianion biradical conveniently produced by noncovalent intermolecular CT interaction between anthraquinone (AQ) and potassium tert-butoxide (KOtBu). Essentially, CT from KOtBu to AQ boosts absorption bands from the UV to visible and near-infrared (NIR) range, enabling AQ-KOtBu to have new absorption bands around 400, 550, and 900 nm. The absorption bands of AQ-KOtBu are dramatically enhanced after blue-to-green or NIR light excitation. Interestingly, both ground state AQ-KOtBu (C(1)) and photoexcited AQ-KOtBu (C(2)) are quenched by oxygen to produce singlet oxygen. Furthermore, C(1) can be photoactivated by purged nitrogen in solution, and C(2) can be regenerated after the photoexcitation and purged nitrogen in solution, which may serve as a photosensitizer under visible and NIR light excitation.
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Affiliation(s)
- Guanheng Huang
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structure Materials of Guangdong Providence, Shantou University, Shantou 515063, China
| | - Jiayu Li
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structure Materials of Guangdong Providence, Shantou University, Shantou 515063, China
| | - Ziqi Deng
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structure Materials of Guangdong Providence, Shantou University, Shantou 515063, China
| | - Jinghong Li
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structure Materials of Guangdong Providence, Shantou University, Shantou 515063, China
| | - Shanshan Sun
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structure Materials of Guangdong Providence, Shantou University, Shantou 515063, China
| | - Liang Xu
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structure Materials of Guangdong Providence, Shantou University, Shantou 515063, China
- Chemistry and Chemical Engineering Guangdong Laboratory, Shantou 515031, P. R. China
| | - Li Dang
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structure Materials of Guangdong Providence, Shantou University, Shantou 515063, China
| | - Ming-De Li
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structure Materials of Guangdong Providence, Shantou University, Shantou 515063, China
- Chemistry and Chemical Engineering Guangdong Laboratory, Shantou 515031, P. R. China
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2
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Sohora M, Mandić L, Basarić N. [3 + 2] Cycloaddition with photogenerated azomethine ylides in β-cyclodextrin. Beilstein J Org Chem 2020; 16:1296-1304. [PMID: 32566032 PMCID: PMC7296198 DOI: 10.3762/bjoc.16.110] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 05/28/2020] [Indexed: 11/23/2022] Open
Abstract
Stability constants for the inclusion complexes of cyclohexylphthalimide 2 and adamantylphthalimide 3 with β-cyclodextrin (β-CD) were determined by 1H NMR titration, K = 190 ± 50 M-1, and K = 2600 ± 600 M-1, respectively. Photochemical reactivity of the inclusion complexes 2@β-CD and 3@β-CD was investigated, and we found out that β-CD does not affect the decarboxylation efficiency, while it affects the subsequent photochemical H-abstraction, resulting in different product distribution upon irradiation in the presence of β-CD. The formation of ternary complexes with acrylonitrile (AN) and 2@β-CD or 3@β-CD was also essayed by 1H NMR. Although the formation of such complexes was suggested, stability constants could not be determined. Irradiation of 2@β-CD in the presence of AN in aqueous solution where cycloadduct 7 was formed highly suggests that decarboxylation and [3 + 2] cycloaddition take place in the ternary complex, whereas such a reactivity from bulky adamantane 3 is less likely. This proof of principle that decarboxylation and cycloaddition can be performed in the β-CD cavity has a significant importance for the design of new supramolecular systems for the control of photoreactivity.
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Affiliation(s)
- Margareta Sohora
- Department of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička cesta 54, 10 000 Zagreb, Croatia. Fax: +385 1 4680 195; Tel: +385 12 4561 141
| | - Leo Mandić
- Department of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička cesta 54, 10 000 Zagreb, Croatia. Fax: +385 1 4680 195; Tel: +385 12 4561 141
- Department of Material Chemistry, Ruđer Bošković Institute, Bijenička cesta 54, 10 000 Zagreb, Croatia
| | - Nikola Basarić
- Department of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička cesta 54, 10 000 Zagreb, Croatia. Fax: +385 1 4680 195; Tel: +385 12 4561 141
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3
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Mandić L, Džeba I, Jadreško D, Mihaljević B, Biczók L, Basarić N. Photophysical properties and electron transfer photochemical reactivity of substituted phthalimides. NEW J CHEM 2020. [DOI: 10.1039/d0nj03465g] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Substituents on phthalimide affect its photophysics and photochemical reactivity. Electron donors generally result in low quantum yields of intersystem crossing and reactivity from singlet excited states.
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Affiliation(s)
- Leo Mandić
- Department of Organic Chemistry and Biochemistry
- Ruđer Bošković Institute
- 10000 Zagreb
- Croatia
- Department of Material Chemistry
| | - Iva Džeba
- Department of Material Chemistry
- Ruđer Bošković Institute
- 10000 Zagreb
- Croatia
| | - Dijana Jadreško
- Division for Marine and Environmental Research
- Ruđer Bošković Institute
- 10000 Zagreb
- Croatia
| | - Branka Mihaljević
- Department of Material Chemistry
- Ruđer Bošković Institute
- 10000 Zagreb
- Croatia
| | - László Biczók
- Institute of Materials and Environmental Chemistry
- Research Centre for Natural Sciences
- 1519 Budapest
- Hungary
| | - Nikola Basarić
- Department of Organic Chemistry and Biochemistry
- Ruđer Bošković Institute
- 10000 Zagreb
- Croatia
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4
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Ma L, Zhao Q, Zhang X, Chen X. A tunable photo-release mechanism of phototrigger compound varying the pH value and excitation wavelength. Chem Phys Lett 2019. [DOI: 10.1016/j.cplett.2019.06.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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5
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Francés-Monerris A, Hognon C, Miranda MA, Lhiaubet-Vallet V, Monari A. Triplet photosensitization mechanism of thymine by an oxidized nucleobase: from a dimeric model to DNA environment. Phys Chem Chem Phys 2018; 20:25666-25675. [PMID: 30298156 DOI: 10.1039/c8cp04866e] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Nucleic acids are constantly exposed to external agents that can induce chemical and photochemical damage. In spite of the great advances achieved in the last years, some molecular mechanisms of DNA damage are not completely understood yet. A recent experimental report (I. Aparici-Espert et al., ACS Chem. Biol. 2018, 13, 542) proved the ability of 5-formyluracil (ForU), a common oxidatively generated product of thymine, to act as an intrinsic sensitizer of nucleic acids, causing single strand breaks and cyclobutane pyrimidine dimers in plasmid DNA. In the present contribution, we use theoretical methodologies to study the triplet photosensitization mechanism of thymine exerted by ForU in a model dimer and in DNA environment. The photochemical pathways in the former system are described combining the CASPT2 and TD-DFT methods, whereas molecular dynamics simulations and QM/MM calculations are employed for the DNA duplex. It is unambiguously shown that the 1n,π* state localised in ForU mediates the population of the triplet manifold, most likely the 3π,π* state centred in ForU, whereas the 3π,π* state localized in thymine can be populated via triplet-triplet energy transfer given the small energy barrier of <0.23 eV determined for this pathway.
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6
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Zvereva E, Segarra-Martí J, Marazzi M, Brazard J, Nenov A, Weingart O, Léonard J, Garavelli M, Rivalta I, Dumont E, Assfeld X, Haacke S, Monari A. The effect of solvent relaxation in the ultrafast time-resolved spectroscopy of solvated benzophenone. Photochem Photobiol Sci 2018; 17:323-331. [DOI: 10.1039/c7pp00439g] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Modeling time-resolved spectra to unravel ultra fast solvent reorganization.
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7
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Dong X, Hu P, Shen W, Li Z, Liu R, Liu X. Carbanion as a Superbase for Catalyzing Thiol⁻Epoxy Photopolymerization. Polymers (Basel) 2017; 9:E400. [PMID: 30965703 PMCID: PMC6418981 DOI: 10.3390/polym9090400] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 08/22/2017] [Accepted: 08/25/2017] [Indexed: 11/21/2022] Open
Abstract
Photobase generator (PBG)-mediated thiol⁻epoxy photopolymerization has received widedspread attention due to its versatility in various applications. Currently, nearly all reported PBGs release amines as active species. The formed amines induce odor, yellowing, and potential toxicity. In this study, a series of novel thioxanthone-based PBGs, which were able to generate carbanion via decarboxylation under LED light irradiation, were designed and straightforwardly prepared. The formed carbanion can be used as a superbase to catalyze thiol⁻epoxy polymerization efficiently. Investigation on ¹H NMR and FT-IR confirmed the generation of carbanion intermediates. The counteranion significantly affected the photodecarboxylation efficiency. The study of photopolymerization tests, based on real-time FT-IR and dielectric analysis measurements, indicated that the generated carbanion exhibited faster polymerization rate and higher epoxy conversion than traditional superbase 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU). In differential scanning calorimeter, thermogravimetric, and nanoindentation tests, comparable thermal and mechanical properties of the photocured films catalyzed by novel PBGs were obtained. The high initiation ability combined with straightforward synthesis makes these PBGs promising candidates for commercialization.
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Affiliation(s)
- Xiaoqing Dong
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, Jiangsu, China.
- Collaborative Innovation Centre for Petrochemical New Materials, AnHui Province Key Laboratory of Optoelectronic and Magnetism Functional Materials, School of Chemistry and Chemical Engineering, Anqing Normal University, Anqing 246013, Anhui, China.
| | - Peng Hu
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, Jiangsu, China.
| | - Weizhen Shen
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, Jiangsu, China.
| | - Zhiquan Li
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, Jiangsu, China.
| | - Ren Liu
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, Jiangsu, China.
| | - Xiaoya Liu
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, Jiangsu, China.
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8
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Bignon E, Marazzi M, Besancenot V, Gattuso H, Drouot G, Morell C, Eriksson LA, Grandemange S, Dumont E, Monari A. Ibuprofen and ketoprofen potentiate UVA-induced cell death by a photosensitization process. Sci Rep 2017; 7:8885. [PMID: 28827702 PMCID: PMC5566383 DOI: 10.1038/s41598-017-09406-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 07/25/2017] [Indexed: 11/23/2022] Open
Abstract
Nonsteroidal 2-arylproprionic acids are widely used, over-the-counter, anti-inflammatory drugs. Photosensitivity is a commonly overlooked adverse effect of these drugs. Based on the combined use of cell viability assays and molecular modeling, we prove and rationalize the photochemical pathways triggering photosensitization for two drugs, ibuprofen and ketoprofen. As its parent compound benzophenone, ketoprofen produces singlet oxygen, upon triplet manifold population. However, ibuprofen and ketoprofen photodissociate and hence may generate two highly reactive radicals. The formation of metastable aggregates between the two drugs and B-DNA is also directly probed by molecular dynamics. Our approach characterizes the coupled influence of the drug's intrinsic photochemistry and the interaction pattern with DNA. The photosensitization activity of nonsteroidal 2-arylproprionic acids, being added to gels and creams for topical use, should be crucially analyzed and rationalized to enact the proper preventive measures.
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Affiliation(s)
- Emmanuelle Bignon
- Institut des Sciences Analytiques, UMR 5280, Université de Lyon1 (UCBL) CNRS, ENS Lyon, Lyon, France
- Université de Lyon, ENS de Lyon, CNRS, Université Lyon 1, Laboratoire de Chimie UMR 5182, F69342, Lyon, France
| | - Marco Marazzi
- Theory-Modeling-Simulation, Université de Lorraine - Nancy, SRSMC, Boulevard des Aiguillettes, Vandoeuvre-lès-Nancy, Nancy, France
- Theory-Modeling-Simulation, CNRS, SRSMC, Boulevard des Aiguillettes, Vandoeuvre-lès-Nancy, Nancy, France
| | - Vanessa Besancenot
- CRAN, UMR 7039 Université de Lorraine-Nancy, Vandoeuvre-lès-Nancy, Nancy, France
- CRAN, UMR 7039 CNRS, Vandoeuvre-lès-Nancy, Nancy, France
| | - Hugo Gattuso
- Theory-Modeling-Simulation, Université de Lorraine - Nancy, SRSMC, Boulevard des Aiguillettes, Vandoeuvre-lès-Nancy, Nancy, France
- Theory-Modeling-Simulation, CNRS, SRSMC, Boulevard des Aiguillettes, Vandoeuvre-lès-Nancy, Nancy, France
| | - Guillaume Drouot
- CRAN, UMR 7039 Université de Lorraine-Nancy, Vandoeuvre-lès-Nancy, Nancy, France
- CRAN, UMR 7039 CNRS, Vandoeuvre-lès-Nancy, Nancy, France
| | - Christophe Morell
- Institut des Sciences Analytiques, UMR 5280, Université de Lyon1 (UCBL) CNRS, ENS Lyon, Lyon, France
| | - Leif A Eriksson
- Department of Chemistry & Molecular Biology, University of Gothenburg, Medicinaregatan 9 c, 40530, Göteborg, Sweden
| | - Stephanie Grandemange
- CRAN, UMR 7039 Université de Lorraine-Nancy, Vandoeuvre-lès-Nancy, Nancy, France.
- CRAN, UMR 7039 CNRS, Vandoeuvre-lès-Nancy, Nancy, France.
| | - Elise Dumont
- Université de Lyon, ENS de Lyon, CNRS, Université Lyon 1, Laboratoire de Chimie UMR 5182, F69342, Lyon, France.
| | - Antonio Monari
- Theory-Modeling-Simulation, Université de Lorraine - Nancy, SRSMC, Boulevard des Aiguillettes, Vandoeuvre-lès-Nancy, Nancy, France.
- Theory-Modeling-Simulation, CNRS, SRSMC, Boulevard des Aiguillettes, Vandoeuvre-lès-Nancy, Nancy, France.
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9
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pH Dependent Photodeprotection of Formaldehyde: Homolytic C-C Scission in Acidic Aqueous Solution versus Heterolytic C-C Scission in Basic Aqueous Solution. J Org Chem 2017; 82:3425-3431. [PMID: 28224790 DOI: 10.1021/acs.joc.6b02756] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The photodeprotection of formaldehyde was investigated for 3-(1-hydroxypropan-2-yl)benzophenone (3-HPBP) with ultrafast time-resolved spectroscopy. The femtosecond transient absorption results indicated the singlet excited state of 3-HPBP transformed efficiently into its triplet state by a fast intersystem crossing. In acidic (pH = 0) and basic (pH = 12.5) aqueous solutions, the triplet intermediate was a key precursor for the deprotection of formaldehyde via two different pathways. However, little photodeprotection was observed in neutral (pH = 7) aqueous solution where the triplet intermediate appeared to undergo a proton coupled electron transfer process to form a ketyl radical transient. The important benzylic biradical intermediates seen in the acidic and basic aqueous solutions were identified by time-resolved resonance Raman spectra whose vibrational frequency patterns were consistent with DFT calculation results for the benzylic biradical intermediate. The results here indicate that the β-carbon alcohol group of the triplet state 3-HPBP is deprotonated in basic aqueous solutions and this leads to a heterolytic C-C bond cleavage to deprotect formaldehyde and produce the benzylic carbanion triplet state species, whereas protonation of the carbonyl moiety of the triplet state 3-HPBP leads to direct generation of a benzylic biradical intermediate and the deprotection of formaldehyde in acidic aqueous solutions via a homolytic C-C bond cleavage.
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10
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Mandić L, Mlinarić-Majerski K, Griesbeck AG, Basarić N. Photodecarboxylation of Adamantane Amino Acids Activated by Phthalimide. European J Org Chem 2016. [DOI: 10.1002/ejoc.201600491] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Leo Mandić
- Department of Organic Chemistry and Biochemistry; Ruđer Bošković Institute; Bijenička cesta 54 10000 Zagreb Croatia
| | - Kata Mlinarić-Majerski
- Department of Organic Chemistry and Biochemistry; Ruđer Bošković Institute; Bijenička cesta 54 10000 Zagreb Croatia
| | - Axel G. Griesbeck
- Department of Chemistry; University of Cologne; Greinstr. 4 50939 Cologne Germany
| | - Nikola Basarić
- Department of Organic Chemistry and Biochemistry; Ruđer Bošković Institute; Bijenička cesta 54 10000 Zagreb Croatia
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11
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Liu M, Li MD, Huang J, Li T, Liu H, Li X, Phillips DL. Substituent Effects on the Photodeprotection Reactions of Selected Ketoprofen Derivatives in Phosphate Buffered Aqueous Solutions. Sci Rep 2016; 6:21606. [PMID: 26899243 PMCID: PMC4761923 DOI: 10.1038/srep21606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 01/27/2016] [Indexed: 11/15/2022] Open
Abstract
Photodeprotection is an important reaction that has been attracting broad interest for use in a variety of applications. Recent advances in ultrafast and vibrational time-resolved spectroscopies can facilitate obtaining data to help unravel the reaction mechanisms involving in the photochemical reactions of interest. The kinetics and reaction mechanisms for the photodeprotection reactions of ketoprofen derivatives containing three different substituents (ibuprofen, Br and I) were investigated by femtosecond transient absorption (fs-TA) and nanosecond time-resolved resonance Raman (ns-TR3) spectroscopy methods in phosphate buffered solutions (PBS). Fs-TA allows us to detect the decay kinetics of the triplet species as the key precursor for formation of a carbanion species for three different substituents attached to ketoprofen. To characterize the structural and electronic properties of the corresponding carbanion and triplet intermediates, TR3 spectroscopic experiments were conducted. The transient spectroscopy work reveals that the different substituents affect the photodecarboxylation reaction to produce carbon dioxide which in turn influences the generation of the carbanion species which determines the rate of the photorelease of the functional groups attached on the ketoprofen parent molecule. The fingerprint TR3 spectroscopy results suggest that ketoprofen derivatives may be deactivated to produce a triplet carbanion when increasing the atom mass of the halogen atoms.
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Affiliation(s)
- Mingyue Liu
- Department of Chemistry, the University of Hong Kong, Pokfulam Road, Hong Kong
| | - Ming-De Li
- Department of Chemistry, the University of Hong Kong, Pokfulam Road, Hong Kong
| | - Jinqing Huang
- Department of Chemistry, the University of Hong Kong, Pokfulam Road, Hong Kong
| | - Tianlu Li
- Department of Chemistry, the University of Hong Kong, Pokfulam Road, Hong Kong
| | - Han Liu
- Department of Chemistry, the University of Hong Kong, Pokfulam Road, Hong Kong
| | - Xuechen Li
- Department of Chemistry, the University of Hong Kong, Pokfulam Road, Hong Kong
| | - David Lee Phillips
- Department of Chemistry, the University of Hong Kong, Pokfulam Road, Hong Kong
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12
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Du L, Li MD, Zhang Y, Xue J, Zhang X, Zhu R, Cheng SC, Li X, Phillips DL. Photoconversion of β-Lapachone to α-Lapachone via a Protonation-Assisted Singlet Excited State Pathway in Aqueous Solution: A Time-Resolved Spectroscopic Study. J Org Chem 2015; 80:7340-50. [DOI: 10.1021/acs.joc.5b00086] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Lili Du
- Department of Chemistry, The University of Hong Kong, Hong Kong S.A.R., China
| | - Ming-De Li
- Department of Chemistry, The University of Hong Kong, Hong Kong S.A.R., China
| | - Yanfeng Zhang
- Department of Chemistry, The University of Hong Kong, Hong Kong S.A.R., China
| | - Jiadan Xue
- Department
of Chemistry, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Xiting Zhang
- Department of Chemistry, The University of Hong Kong, Hong Kong S.A.R., China
| | - Ruixue Zhu
- Department of Chemistry, The University of Hong Kong, Hong Kong S.A.R., China
| | - Shun Cheung Cheng
- Department of Chemistry, The University of Hong Kong, Hong Kong S.A.R., China
| | - Xuechen Li
- Department of Chemistry, The University of Hong Kong, Hong Kong S.A.R., China
| | - David Lee Phillips
- Department of Chemistry, The University of Hong Kong, Hong Kong S.A.R., China
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13
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Li MD, Dang L, Liu M, Du L, Zheng X, Phillips DL. Ultrafast Time Resolved Spectroscopic Studies on the Generation of the Ketyl-Sugar Biradical by Intramolecular Hydrogen Abstraction among Ketoprofen and Purine Nucleoside Dyads. J Org Chem 2015; 80:3462-70. [DOI: 10.1021/acs.joc.5b00047] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ming-De Li
- Department
of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong S.A.R., P.R. China
| | - Li Dang
- Department
of Chemistry, South University of Science and Technology of China, Shenzhen, Guangdong 518055, China
| | - Mingyue Liu
- Department
of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong S.A.R., P.R. China
| | - Lili Du
- Department
of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong S.A.R., P.R. China
| | - Xuming Zheng
- Department
of Chemistry, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - David Lee Phillips
- Department
of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong S.A.R., P.R. China
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14
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Wang YH, Wan P. Ketoprofen as a photoinitiator for anionic polymerization. Photochem Photobiol Sci 2015; 14:1120-6. [DOI: 10.1039/c4pp00454j] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new photoinitiating system for anionic polymerization of acrylates through the efficient photodecarboxylation of Ketoprofen is presented.
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Affiliation(s)
- Yu-Hsuan Wang
- Department of Chemistry
- Box 3065
- University of Victoria
- Victoria
- Canada
| | - Peter Wan
- Department of Chemistry
- Box 3065
- University of Victoria
- Victoria
- Canada
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15
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Liu M, Li MD, Xue J, Phillips DL. Time-resolved spectroscopic and density functional theory study of the photochemistry of Irgacure-2959 in an aqueous solution. J Phys Chem A 2014; 118:8701-7. [PMID: 25134065 DOI: 10.1021/jp506099n] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The photocleavage reaction mechanism of 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone (Irgacure-2959) was investigated using femtosecond (fs) and nanosecond (ns) transient absorption (-TA) spectroscopy and also picosecond (ps) and nanosecond (ns) time-resolved resonance Raman (-TR(3)) spectroscopy experiments in a water-rich (volume ratio of acetonitrile/water = 3:7) solution. TA spectroscopy was used to study the dynamics of the benzoyl radical growth and decay as well as to investigate the radical quenching process by the radical scavenger methyl acrylate. ps- and ns-TR(3) spectroscopies were employed to monitor the formation of the benzoyl radical and also to characterize its electronic and structural properties. The fs-TA experiments results indicate that the Irgacure-2959 lowest lying excited singlet state S1 underwent efficient intersystem crossing (ISC) to convert into its triplet state with a time constant of 4 ps. Subsequently, this triplet species dissociated into the benzoyl and alkyl radicals with a corresponding maximum absorption band at 415 nm. The TR(3) results in conjunction with results from DFT calculations confirmed that Irgacure-2959 cleaved into the benzoyl and alkyl radicals at a fast rate on the tens of picosecond time scale.
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Affiliation(s)
- Mingyue Liu
- Department of Chemistry, The University of Hong Kong , Pokfulam Road, Hong Kong S.A.R., P. R. China
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16
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Li MD, Huang J, Liu M, Li S, Ma J, Phillips DL. Investigation of the role of protonation of benzophenone and its derivatives in acidic aqueous solutions using time-resolved resonance Raman spectroscopy: how are ketyl radicals formed in aqueous solutions? J Phys Chem B 2014; 119:2241-52. [PMID: 25141023 DOI: 10.1021/jp505954d] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The formation mechanism of ketyl radicals and several other selective photoreactions of benzophenone and its derivatives are initiated by the protonation of their triplet state and have been investigated using nanosecond time-resolved resonance Raman spectroscopy (ns-TR(3)) in solutions of varying conditions. Evidence is found that the ketyl radical is generated by the combined action of a ketone protonation and a subsequent electron transfer based on the results from previous studies on the photochemistry and photophysics of benzophenone and the ns-TR(3) results reported here for benzophenone, 1,4-dibenzoylbenzene, 3-(hydroxymethyl)benzophenone, and ketoprofen in neutral and acidic solution. In order to better understand the role of the protonated ketone, results are summarized for some selective photochemical reactions of benzophenone and its derivatives induced by protonation in acidic solutions. For the parent benzophenone, the protonation of the ketone leads to the photohydration reactions at the ortho- and meta-positions of the benzene ring in acidic aqueous solutions. For 3-(hydroxymethyl)benzophenone, the protonation promotes an interesting photoredox reaction to become very efficient and the predominant reaction in a pH = 2 aqueous solution. While for ketoprofen, the protonation can initiate a solvent-mediated excited-state intramolecular proton transfer (ESIPT) from the carboxyl group to the carbonyl group that then leads to a decarboxylation reaction in a pH = 0 acidic aqueous solution. We briefly discuss the key role of the protonation of the ketone in the photochemistry of these aromatic ketones.
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Affiliation(s)
- Ming-De Li
- Department of Chemistry, The University of Hong Kong , Pokfulam Road, Hong Kong, People's Republic of China
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