1
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Qiu Y, Du L, Cady SD, Phillips DL, Winter AH. Optical and EPR Detection of a Triplet Ground State Phenyl Nitrenium Ion. J Am Chem Soc 2024; 146:10679-10686. [PMID: 38579336 DOI: 10.1021/jacs.4c00511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2024]
Abstract
Nitrenium ions are important reactive intermediates participating in the synthetic chemistry and biological processes. Little is known about triplet phenyl nitrenium ions regarding their reactivity, lifetimes, spectroscopic features, and electronic configurations, and no ground state triplet nitrenium ion has been directly detected. In this work, m-pyrrolidinyl-phenyl hydrazine hydrochloride (1) is synthesized as the photoprecursor to photochemically generate the corresponding m-pyrrolidinyl-phenyl nitrenium ion (2), which is computed to adopt a π, π* triplet ground state. A combination of femtosecond (fs) and nanosecond (ns) transient absorption (TA) spectroscopy, cryogenic continuous-wave electronic paramagnetic resonance (CW-EPR) spectroscopy, computational analysis, and photoproduct studies was performed to elucidate the photolysis pathway of 1 and offers the first direct experimental detection of a ground state triplet phenyl nitrenium ion. Upon photoexcitation, 1 forms S1, where bond heterolysis occurs and the NH3 leaving group is extruded in 1.8 ps, generating a vibrationally hot, spin-conserving closed-shell singlet phenyl nitrenium ion (12) that undergoes vibrational cooling in 19 ps. Subsequent intersystem crossing takes place in 0.5 ns, yielding the ground state triplet phenyl nitrenium ion (32), with a lifetime of 0.8 μs. Unlike electrophilic singlet phenyl nitrenium ions, which react rapidly with nucleophiles, this triplet phenyl nitrenium reacts through sequential H atom abstractions, resulting in the eventual formation of the reduced m-pyrrolidinyl-aniline as the predominant stable photoproduct. Supporting the triplet ground state, continuous irradiation of 1 in a glassy matrix at 80 K in an EPR spectrometer forms a paramagnetic triplet species, consistent with a triplet nitrenium ion.
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Affiliation(s)
- Yunfan Qiu
- Department of Chemistry, Iowa State University, 2101d Hach Hall, Ames, Iowa 50011, United States
| | - Lili Du
- Department of Chemistry, University of Hong Kong, Pokfulam Road, Hong Kong, S.A.R 11111, P. R. China
| | - Sarah D Cady
- Department of Chemistry, Iowa State University, 2101d Hach Hall, Ames, Iowa 50011, United States
| | - David Lee Phillips
- Department of Chemistry, University of Hong Kong, Pokfulam Road, Hong Kong, S.A.R 11111, P. R. China
| | - Arthur H Winter
- Department of Chemistry, Iowa State University, 2101d Hach Hall, Ames, Iowa 50011, United States
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2
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Ley C, Siedel A, Bertaux T, Croutxé-Barghorn C, Allonas X. Photochemical Processes of Superbase Generation in Xanthone Carboxylic Salts. Angew Chem Int Ed Engl 2023; 62:e202214784. [PMID: 36533332 DOI: 10.1002/anie.202214784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 12/16/2022] [Accepted: 12/16/2022] [Indexed: 12/23/2022]
Abstract
Photobase generators are species that allow the photocatalysis of various reactions, such as thiol-Michael, thiol-isocyanate, and ring-opening polymerization reactions. However, existing compounds have complex syntheses and low quantum yields. To overcome these problems, photobase generators based on the photodecarboxylation reaction were developed. We synthesized and studied the photochemistry and photophysics of two xanthone photobase, their carboxylic acid precursors, and their photoproducts to understand the photobase generation mechanism. We determined accurate quantum yields of triplet states and photobase generation. The effect of the intermediate radical preceding the base release was demonstrated. We characterized the photophysics of the photobase by femtosecond spectroscopy and showed that the photodecarboxylation process occurred from the second excited triplet state with a rate constant of 2.2×109 s-1 .
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Affiliation(s)
- Christian Ley
- Laboratoire de Photochimie et d'Ingénierie Macromoléculaire, Université de Haute Alsace, 3b rue A. Werner, 68200, Mulhouse, France
| | - Antoine Siedel
- Laboratoire de Photochimie et d'Ingénierie Macromoléculaire, Université de Haute Alsace, 3b rue A. Werner, 68200, Mulhouse, France
| | - Tony Bertaux
- Laboratoire de Photochimie et d'Ingénierie Macromoléculaire, Université de Haute Alsace, 3b rue A. Werner, 68200, Mulhouse, France
| | - Céline Croutxé-Barghorn
- Laboratoire de Photochimie et d'Ingénierie Macromoléculaire, Université de Haute Alsace, 3b rue A. Werner, 68200, Mulhouse, France
| | - Xavier Allonas
- Laboratoire de Photochimie et d'Ingénierie Macromoléculaire, Université de Haute Alsace, 3b rue A. Werner, 68200, Mulhouse, France
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3
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Huang G, Zhou C, Liang R, Sun S, Deng Z, Li J, Dang L, Phillips DL, Li MD. Ultrafast Time-Resolved Spectroscopic Study on the Photophysical and Photochemical Reaction Mechanisms of ortho-Methylbenzophenone in Selected Solutions. J Phys Chem B 2022; 126:9388-9398. [PMID: 36331406 DOI: 10.1021/acs.jpcb.2c06452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The photophysical and photochemical reaction pathways of ortho-methylbenzophenone (o-MeBP) in different solutions were investigated by employing femtosecond to nanosecond transient absorption and nanosecond time-resolved resonance Raman spectroscopy methods. In pure acetonitrile, neutral or pH 1 aqueous solutions, o-MeBP exhibit similar excited-state evolutions upon excitation in which o-MeBP will experience excitation to an excited state then undergo intersystem crossing and solvent arrangement followed by 1,5 hydrogen atom transfer processes to form the first singlet excited state, triplet state (n, π*), biradical intermediates, and enol form transients, respectively. However, in a pH 0 acidic solution, the protonation of o-MeBP will form the cation biradical intermediate that facilitates radical coupling to generate a benzocyclobutanol product, which causes a dramatic reduction of the lifetime of the enol form transients. In contrast, in sodium bicarbonate solution, the biradical intermediate may be quenched by the bicarbonate ion to construct a C-C bond and form the carboxylic acid that causes a fast decay of biradical intermediate. These results demonstrate that the photophysical and photochemical reaction pathways of o-MeBP are pH-dependent in aqueous solution which may be very useful for the capture of CO2 capture by photoexcitation of aromatic ketones.
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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, Shantou515063, China.,Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, PR China
| | - Chen Zhou
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structure Materials of Guangdong Providence, Shantou University, Shantou515063, China
| | - Runhui Liang
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, PR China
| | - Shanshan Sun
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structure Materials of Guangdong Providence, Shantou University, Shantou515063, China
| | - Ziqi Deng
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structure Materials of Guangdong Providence, Shantou University, Shantou515063, China
| | - Jiayu Li
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structure Materials of Guangdong Providence, Shantou University, Shantou515063, China
| | - Li Dang
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structure Materials of Guangdong Providence, Shantou University, Shantou515063, China
| | - David Lee Phillips
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, PR China
| | - Ming-De Li
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structure Materials of Guangdong Providence, Shantou University, Shantou515063, China
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4
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Mastova AV, Selyutina OY, Polyakov NE. Stereoselectivity of Interaction of Nonsteroidal Anti-Inflammatory Drug S-Ketoprofen with L/D-Tryptophan in Phospholipid Membranes. MEMBRANES 2022; 12:membranes12050460. [PMID: 35629787 PMCID: PMC9147405 DOI: 10.3390/membranes12050460] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Revised: 04/07/2022] [Accepted: 04/21/2022] [Indexed: 02/04/2023]
Abstract
The mechanisms of stereoselectivity of the interaction of chiral drugs with active sites of enzymes and cell receptors attract significant attention. The first reason is the difference in therapeutic activity of the enantiomers of the common drugs. Another reason is the interest in the role of chiral inversion of amino acids involved in various peptides in the development of many diseases including Alzheimer’s, Parkinson’s, type II diabetes, and a number of other pathological conditions. In our study we use elementary chemical process—electron transfer (ET) to simulate individual stages of ligand–receptor and enzyme–substrate interactions. In particular, previous studies of photoinduced ET in chiral donor-acceptor dyads consisting of the nonsteroidal anti-inflammatory drug (R/S)-ketoprofen and (L)-tryptophan show the stereo and spin selectivity of ET in diastereomers. The present study is devoted to the interaction of (S)-ketoprofen with L- and D-enantiomers of tryptophan in homogeneous aqueous solution and in phospholipid membranes. The study was done using the NMR technique and molecular modeling. These approaches confirm efficient penetration of ketoprofen into the lipid bilayer and binding with tryptophan molecule. The short-lived paramagnetic intermediates formed during the photoinduced ET from electron donor tryptophan to ketoprofen have been detected using the chemically induced dynamic nuclear polarization (CIDNP) technique. It was found that S-ketoprofen interacts stereoselectively with tryptophan enantiomers in the lipid membrane. The formation of the ketyl radical of ketoprofen under irradiation leads to the oxidation of membrane lipids and may be the cause of ketoprofen phototoxicity. However, in contrast to a homogeneous solution in phosphate buffer saline, where the amino acid tryptophan accelerates the photodecomposition of KP due to intramolecular hydrogen transfer, tryptophan in a lipid membrane significantly reduces the rate of photodegradation due to a reversible electron (or hydrogen) transfer reaction. The stereoselectivity in the rate of KP and lipids decomposition under UV irradiation of S-ketoprofen in the presence of tryptophan enantiomers in lipid bilayer has been detected.
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5
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Kashihara W, Shinoda M, Tsuchiya K, Isozaki T, Mijiddorj B, Ueda K, Suzuki T. Photochemical Reaction of Ketoprofen with Proteinogenic Amino Acids. J Phys Chem B 2022; 126:2098-2107. [PMID: 35142495 DOI: 10.1021/acs.jpcb.1c10108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Ketoprofen (KP) is one of the most popular nonsteroidal anti-inflammatory drugs; however, drug-induced photosensitivity of KP has been reported as a serious adverse effect. KP incorporated into a protein can produce an allergen under UV irradiation, which causes drug-induced photosensitivity. The photochemistry of KP with 20 kinds of proteinogenic amino acids in phosphate buffer solutions at pH 7.4 was studied by transient absorption spectroscopy. The KP carboxylate anion (KP-) gave rise to a carbanion via a decarboxylation within a laser pulse, and the carbanion yielded 3-ethylbenzophenone ketyl biradical (3-EBPH) through a proton transfer reaction. Twelve kinds of proteinogenic amino acids obviously accelerated the reaction. Structural information on the complexes of KP docked in the binding sites of human serum albumin (HSA) was obtained by molecular mechanics (MM) and molecular dynamics (MD) calculations. The photochemical reaction of KP- with amino acid residues in HSA was discussed on the basis of the experimental and calculational results. The information on the reactivity of KP with the amino acids and the stable structures of the KP-HSA complexes should be essential for understanding of the initial step for drug-induced photosensitivity.
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Affiliation(s)
- Wataru Kashihara
- Department of Chemistry and Biological Science, Aoyama Gakuin University, 5-10-1 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5258, Japan
| | - Mio Shinoda
- Department of Chemistry and Biological Science, Aoyama Gakuin University, 5-10-1 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5258, Japan
| | - Kiyoka Tsuchiya
- Department of Chemistry and Biological Science, Aoyama Gakuin University, 5-10-1 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5258, Japan
| | - Tasuku Isozaki
- Department of Chemistry and Biological Science, Aoyama Gakuin University, 5-10-1 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5258, Japan.,Division of Natural Sciences, College of Arts and Sciences, J. F. Oberlin University, 3758 Tokiwa-machi, Machida, Tokyo 194-0294, Japan
| | - Batsaikhan Mijiddorj
- Laboratory of Bioinformatics and Systems Biology, Department of Biology, School of Arts and Sciences, National University of Mongolia, Ulaanbaatar 14201, Mongolia
| | - Kazuyoshi Ueda
- Department of Chemistry and Biological Science, Aoyama Gakuin University, 5-10-1 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5258, Japan.,Graduate School of Engineering, Yokohama National University,79-5 Tokiwadai, Hodogaya-ku, Yokohama, Kanagawa 240-8501, Japan
| | - Tadashi Suzuki
- Department of Chemistry and Biological Science, Aoyama Gakuin University, 5-10-1 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5258, Japan
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6
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Kashihara W, Takeyama J, Suzuki T. Diffusion process in photoreaction of ketoprofen probed by transient grating method. J Photochem Photobiol A Chem 2020. [DOI: 10.1016/j.jphotochem.2020.112623] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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7
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New insights into the nature of short-lived paramagnetic intermediates of ketoprofen. Photo-CIDNP study. J Photochem Photobiol A Chem 2020. [DOI: 10.1016/j.jphotochem.2020.112383] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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8
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Kashihara W, Inoue M, Tanabe S, Miyata S, Sakai K, Isozaki T, Suzuki T. Hydrogen Abstraction of Ketoprofen in the Excited Triplet State with Indole and Methylindoles. J Phys Chem B 2019; 123:9388-9394. [PMID: 31596088 DOI: 10.1021/acs.jpcb.9b06786] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Relaxation of excited states and reactivity of ketoprofen (KP), one of the most popular nonsteroidal anti-inflammatory drugs, with indole and methylindoles have been studied with transient absorption and quantum chemical calculations. KP in the excited triplet state, 3KP*, abstracted a hydrogen atom from indole and methylindoles to afford a ketyl radical and a counter radical. The bimolecular quenching rate constants of 3KP* by indole and methylindoles, kq, and the hydrogen atom abstraction rate constants, kr, were obtained. The kr values for methylindoles were larger than that for indole; in addition, transient spectra at around 350 nm, assigned to the corresponding C-centered radical, was observed. These results indicate that 3KP* abstracts a hydrogen atom of the methyl group as well as that of N-H in the indole frame. These findings give us information on the reactivity of excited KP in the vicinity of tryptophan in a KP-protein complex, which will ultimately cause photosensitization on human skin.
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Affiliation(s)
- Wataru Kashihara
- Department of Chemistry and Biological Science , Aoyama Gakuin University , 5-10-1 Fuchinobe , Chuo-ku, Sagamihara , Kanagawa 252-5258 , Japan
| | - Mana Inoue
- Department of Chemistry and Biological Science , Aoyama Gakuin University , 5-10-1 Fuchinobe , Chuo-ku, Sagamihara , Kanagawa 252-5258 , Japan
| | - Shunsuke Tanabe
- Department of Chemistry and Biological Science , Aoyama Gakuin University , 5-10-1 Fuchinobe , Chuo-ku, Sagamihara , Kanagawa 252-5258 , Japan
| | - Shoma Miyata
- Department of Chemistry and Biological Science , Aoyama Gakuin University , 5-10-1 Fuchinobe , Chuo-ku, Sagamihara , Kanagawa 252-5258 , Japan
| | - Kohei Sakai
- Department of Chemistry and Biological Science , Aoyama Gakuin University , 5-10-1 Fuchinobe , Chuo-ku, Sagamihara , Kanagawa 252-5258 , Japan
| | - Tasuku Isozaki
- Department of Chemistry and Biological Science , Aoyama Gakuin University , 5-10-1 Fuchinobe , Chuo-ku, Sagamihara , Kanagawa 252-5258 , Japan.,Division of Natural Sciences, College of Arts and Sciences , J. F. Oberlin University , 3758 Tokiwa-machi , Machida, Tokyo 194-0294 , Japan
| | - Tadashi Suzuki
- Department of Chemistry and Biological Science , Aoyama Gakuin University , 5-10-1 Fuchinobe , Chuo-ku, Sagamihara , Kanagawa 252-5258 , Japan
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9
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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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10
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Li MD, Wong NK, Xiao J, Zhu R, Wu L, Dai SY, Chen F, Huang G, Xu L, Bai X, Geraskina MR, Winter AH, Chen X, Liu Y, Fang W, Yang D, Phillips DL. Dynamics of Oxygen-Independent Photocleavage of Blebbistatin as a One-Photon Blue or Two-Photon Near-Infrared Light-Gated Hydroxyl Radical Photocage. J Am Chem Soc 2018; 140:15957-15968. [PMID: 30269478 DOI: 10.1021/jacs.8b10235] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Development of versatile, chemically tunable photocages for photoactivated chemotherapy (PACT) represents an excellent opportunity to address the technical drawbacks of conventional photodynamic therapy (PDT) whose oxygen-dependent nature renders it inadequate in certain therapy contexts such as hypoxic tumors. As an alternative to PDT, oxygen free mechanisms to generate cytotoxic reactive oxygen species (ROS) by visible light cleavable photocages are in demand. Here, we report the detailed mechanisms by which the small molecule blebbistatin acts as a one-photon blue light-gated or two-photon near-infrared light-gated photocage to directly release a hydroxyl radical (•OH) in the absence of oxygen. By using femtosecond transient absorption spectroscopy and chemoselective ROS fluorescent probes, we analyze the dynamics and fate of blebbistatin during photolysis under blue light. Water-dependent photochemistry reveals a critical process of water-assisted protonation and excited state intramolecular proton transfer (ESIPT) that drives the formation of short-lived intermediates, which surprisingly culminates in the release of •OH but not superoxide or singlet oxygen from blebbistatin. CASPT2//CASSCF calculations confirm that hydrogen bonding between water and blebbistatin underpins this process. We further determine that blue light enables blebbistatin to induce mitochondria-dependent apoptosis, an attribute conducive to PACT development. Our work demonstrates blebbistatin as a controllable photocage for •OH generation and provides insight into the potential development of novel PACT agents.
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Affiliation(s)
- Ming-De Li
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province , Shantou University , Shantou 515063 , China
| | - Nai-Kei Wong
- Department of Chemistry , The University of Hong Kong , Pokfulam Road , Hong Kong , China.,State Key Discipline of Infectious Diseases , Shenzhen Third People's Hospital , Shenzhen 518112 , China
| | - Jia Xiao
- State Key Discipline of Infectious Diseases , Shenzhen Third People's Hospital , Shenzhen 518112 , China
| | - Ruixue Zhu
- Department of Chemistry , The University of Hong Kong , Pokfulam Road , Hong Kong , China
| | - Liangliang Wu
- Department of Chemistry , Beijing Normal University , Xin-wai-da-jie 19 , Beijing 100875 , China
| | - Sheng-Yao Dai
- Department of Chemistry , The University of Hong Kong , Pokfulam Road , Hong Kong , China
| | - Feng Chen
- State Key Discipline of Infectious Diseases , Shenzhen Third People's Hospital , Shenzhen 518112 , China
| | - Guanheng Huang
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province , Shantou University , Shantou 515063 , China
| | - Liang Xu
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province , Shantou University , Shantou 515063 , China
| | - Xiaoyu Bai
- Department of Chemistry , The University of Hong Kong , Pokfulam Road , Hong Kong , China
| | - Margarita R Geraskina
- Department of Chemistry , Iowa State University , 2101d Hach Hall , Ames , Iowa 50011 , United States
| | - Arthur H Winter
- Department of Chemistry , Iowa State University , 2101d Hach Hall , Ames , Iowa 50011 , United States
| | - Xuebo Chen
- Department of Chemistry , Beijing Normal University , Xin-wai-da-jie 19 , Beijing 100875 , China
| | - Yingxia Liu
- State Key Discipline of Infectious Diseases , Shenzhen Third People's Hospital , Shenzhen 518112 , China
| | - Weihai Fang
- Department of Chemistry , Beijing Normal University , Xin-wai-da-jie 19 , Beijing 100875 , China
| | - Dan Yang
- Department of Chemistry , The University of Hong Kong , Pokfulam Road , Hong Kong , China
| | - David Lee Phillips
- Department of Chemistry , The University of Hong Kong , Pokfulam Road , Hong Kong , China
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11
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Li MD, Yan Z, Zhu R, Phillips DL, Aparici-Espert I, Lhiaubet-Vallet V, Miranda MA. Enhanced Drug Photosafety by Interchromophoric Interaction Owing to Intramolecular Charge Separation. Chemistry 2018; 24:6654-6659. [DOI: 10.1002/chem.201800716] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2018] [Indexed: 01/07/2023]
Affiliation(s)
- Ming-De Li
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province; Shantou University; Guangdong 515063 P. R. China
| | - Zhiping Yan
- Department of Chemistry; The University of Hong Kong, Pokfulam Road; Hong Kong S. A. R. P. R. China
| | - Ruixue Zhu
- Department of Chemistry; The University of Hong Kong, Pokfulam Road; Hong Kong S. A. R. P. R. China
| | - David Lee Phillips
- Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province; Shantou University; Guangdong 515063 P. R. China
- Department of Chemistry; The University of Hong Kong, Pokfulam Road; Hong Kong S. A. R. P. R. China
| | - Isabel Aparici-Espert
- Instituto de Tecnología Química UPV-CSIC; Universitat Politècnica de València, Consejo Superior de Investigaciones Científicas; Avda de los Naranjos s/n 46022 Valencia Spain
| | - Virginie Lhiaubet-Vallet
- Instituto de Tecnología Química UPV-CSIC; Universitat Politècnica de València, Consejo Superior de Investigaciones Científicas; Avda de los Naranjos s/n 46022 Valencia Spain
| | - Miguel A. Miranda
- Instituto de Tecnología Química UPV-CSIC; Universitat Politècnica de València, Consejo Superior de Investigaciones Científicas; Avda de los Naranjos s/n 46022 Valencia Spain
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12
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Size-dependent activity and selectivity of carbon dioxide photocatalytic reduction over platinum nanoparticles. Nat Commun 2018; 9:1252. [PMID: 29593250 PMCID: PMC5871894 DOI: 10.1038/s41467-018-03666-2] [Citation(s) in RCA: 181] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Accepted: 03/02/2018] [Indexed: 12/05/2022] Open
Abstract
Platinum nanoparticles (Pt NPs) are one of the most efficient cocatalysts in photocatalysis, and their size determines the activity and the selectivity of the catalytic reaction. Nevertheless, an in-depth understanding of the platinum’s size effect in the carbon dioxide photocatalytic reduction is still lacking. Through analyses of the geometric features and electronic properties with variable-sized Pt NPs, here we show a prominent size effect of Pt NPs in both the activity and selectivity of carbon dioxide photocatalytic reduction. Decreasing the size of Pt NPs promotes the charge transfer efficiency, and thus enhances both the carbon dioxide photocatalytic reduction and hydrogen evolution reaction (HER) activity, but leads to higher selectivity towards hydrogen over methane. Combining experimental results and theoretical calculations, in Pt NPs, the terrace sites are revealed as the active sites for methane generation; meanwhile, the low-coordinated sites are more favorable in the competing HER. Light-driven carbon dioxide conversion into fuels provides a nature-inspired strategy to combat climate change, but how materials do so remains a challenge. Here, the authors prepare metal–semiconductor composites and find platinum-nanoparticle size controls fuel selectivity and activity.
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13
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Direct time-resolved spectroscopic investigation of intramolecular hydrogen atom transfer of deoxyblebbistatin. Chem Phys Lett 2017. [DOI: 10.1016/j.cplett.2017.02.068] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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14
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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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15
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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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16
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Aparici-Espert I, Cuquerella MC, Paris C, Lhiaubet-Vallet V, Miranda MA. Photocages for protection and controlled release of bioactive compounds. Chem Commun (Camb) 2016; 52:14215-14218. [DOI: 10.1039/c6cc08175d] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
A photoactivatable ketoprofen–avobenzone dyad was designed for the protection and controlled release of phototoxic drugs.
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Affiliation(s)
- I. Aparici-Espert
- Instituto Universitario Mixto de Tecnología Química (UPV-CSIC)
- Universitat Politècnica de València
- Consejo Superior de Investigaciones Científicas
- 46022 Valencia
- Spain
| | - M. C. Cuquerella
- Instituto Universitario Mixto de Tecnología Química (UPV-CSIC)
- Universitat Politècnica de València
- Consejo Superior de Investigaciones Científicas
- 46022 Valencia
- Spain
| | - C. Paris
- Instituto Universitario Mixto de Tecnología Química (UPV-CSIC)
- Universitat Politècnica de València
- Consejo Superior de Investigaciones Científicas
- 46022 Valencia
- Spain
| | - V. Lhiaubet-Vallet
- Instituto Universitario Mixto de Tecnología Química (UPV-CSIC)
- Universitat Politècnica de València
- Consejo Superior de Investigaciones Científicas
- 46022 Valencia
- Spain
| | - M. A. Miranda
- Instituto Universitario Mixto de Tecnología Química (UPV-CSIC)
- Universitat Politècnica de València
- Consejo Superior de Investigaciones Científicas
- 46022 Valencia
- Spain
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17
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Li MD, Albright TR, Hanway PJ, Liu M, Lan X, Li S, Peterson J, Winter AH, Phillips DL. Direct Spectroscopic Detection and EPR Investigation of a Ground State Triplet Phenyl Oxenium Ion. J Am Chem Soc 2015. [PMID: 26198984 DOI: 10.1021/jacs.5b06302] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Oxenium ions are important reactive intermediates in synthetic chemistry and enzymology, but little is known of the reactivity, lifetimes, spectroscopic signatures, and electronic configurations of these unstable species. Recent advances have allowed these short-lived ions to be directly detected in solution from laser flash photolysis of suitable photochemical precursors, but all of the studies to date have focused on aryloxenium ions having closed-shell singlet ground state configurations. To study alternative spin configurations, we synthesized a photoprecursor to the m-dimethylamino phenyloxenium ion, which is predicted by both density functional theory and MRMP2 computations to have a triplet ground state electronic configuration. A combination of femtosecond and nanosecond transient absorption spectroscopy, nanosecond time-resolved Resonance Raman spectroscopy (ns-TR(3)), cryogenic matrix EPR spectroscopy, computational analysis, and photoproduct studies allowed us to trace essentially the complete arc of the photophysics and photochemistry of this photoprecursor and permitted a first look at a triplet oxenium ion. Ultraviolet photoexcitation of this precursor populates higher singlet excited states, which after internal conversion to S1 over 800 fs are followed by bond heterolysis in ∼1 ps, generating a hot closed-shell singlet oxenium ion that undergoes vibrational cooling in ∼50 ps followed by intersystem crossing in ∼300 ps to generate the triplet ground state oxenium ion. In contrast to the rapid trapping of singlet phenyloxenium ions by nucleophiles seen in prior studies, the triplet oxenium ion reacts via sequential H atom abstractions on the microsecond time domain to ultimately yield the reduced m-dimethylaminophenol as the only detectable stable photoproduct. Band assignments were made by comparisons to computed spectra of candidate intermediates and comparisons to related known species. The triplet oxenium ion was also detected in the ns-TR(3) experiments, permitting a more clear assignment and identifying the triplet state as the π,π* triplet configuration. The triplet ground state of this ion was further supported by photolysis of the photoprecursor in an ethanol glass at ∼4 K and observing a triplet species by cryogenic EPR spectroscopy.
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Affiliation(s)
- Ming-De Li
- †Department of Chemistry, University of Hong Kong, Pokfulam Road, Hong Kong, S.A.R., P. R. China
| | - Toshia R Albright
- ‡Department of Chemistry, Iowa State University, 2101d Hach Hall, Ames, Iowa 50011, United States
| | - Patrick J Hanway
- ‡Department of Chemistry, Iowa State University, 2101d Hach Hall, Ames, Iowa 50011, United States
| | - Mingyue Liu
- †Department of Chemistry, University of Hong Kong, Pokfulam Road, Hong Kong, S.A.R., P. R. China
| | - Xin Lan
- †Department of Chemistry, University of Hong Kong, Pokfulam Road, Hong Kong, S.A.R., P. R. China
| | - Songbo Li
- †Department of Chemistry, University of Hong Kong, Pokfulam Road, Hong Kong, S.A.R., P. R. China
| | - Julie Peterson
- ‡Department of Chemistry, Iowa State University, 2101d Hach Hall, Ames, Iowa 50011, United States
| | - Arthur H Winter
- ‡Department of Chemistry, Iowa State University, 2101d Hach Hall, Ames, Iowa 50011, United States
| | - David Lee Phillips
- †Department of Chemistry, University of Hong Kong, Pokfulam Road, Hong Kong, S.A.R., P. R. China
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18
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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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19
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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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20
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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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21
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Dai J, Han J, Chen X, Fang W, Ma J, Phillips DL. Water-assisted self-photoredox of 2-(1-hydroxyethyl)-9,10-anthraquinone through a triplet excited state intra-molecular proton transfer pathway. Phys Chem Chem Phys 2015; 17:27001-10. [DOI: 10.1039/c5cp03442f] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A novel self-photoredox reaction for 2-(1-hydroxyethyl)-9,10-anthraquinone has been theoretically rationalized to take place through two steps of triplet excited state intra-molecular proton transfer aided by water wires.
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Affiliation(s)
- Jingze Dai
- Department of Chemistry
- Beijing Normal University
- Beijing 100875
- P. R. China
| | - Juan Han
- Department of Chemistry
- Beijing Normal University
- Beijing 100875
- P. R. China
| | - Xuebo Chen
- Department of Chemistry
- Beijing Normal University
- Beijing 100875
- P. R. China
| | - Weihai Fang
- Department of Chemistry
- Beijing Normal University
- Beijing 100875
- P. R. China
| | - Jiani Ma
- College of Chemistry and Materials Science
- Northwest University
- Xi'an
- P. R. China
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22
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Su T, Li MD, Ma J, Wong N, Phillips DL. Femtosecond Transient Absorption Spectroscopy Study of the Early Events of Norfloxacin in Aqueous Solutions with Varying pH Values. J Phys Chem B 2014; 118:13458-67. [DOI: 10.1021/jp506711f] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Tao Su
- Department
of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
- Department
of Molten Salt Chemistry and Engineering, Shanghai Institute of Applied
Physics, Chinese Academy of Sciences, 2019 Jia Luo Road, Jiading District, Shanghai, P. R. China 201800
| | - Ming-De Li
- Department
of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
| | - Jiani Ma
- Department
of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
| | - Naikei Wong
- Department
of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
| | - David Lee Phillips
- Department
of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
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23
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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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24
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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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25
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Li MD, Hanway PJ, Albright TR, Winter AH, Phillips DL. Direct Spectroscopic Observation of Closed-Shell Singlet, Open-Shell Singlet, and Triplet p-Biphenylyloxenium Ion. J Am Chem Soc 2014; 136:12364-70. [DOI: 10.1021/ja505447q] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ming-De Li
- Department
of Chemistry, University of Hong Kong, Pokfulam Road, Hong Kong S.A.R., P.R. China
| | - Patrick J. Hanway
- Department
of Chemistry, Iowa State University, 2101d Hach Hall, Ames, Iowa 50011, United States
| | - Toshia R. Albright
- Department
of Chemistry, Iowa State University, 2101d Hach Hall, Ames, Iowa 50011, United States
| | - Arthur H. Winter
- Department
of Chemistry, Iowa State University, 2101d Hach Hall, Ames, Iowa 50011, United States
| | - David Lee Phillips
- Department
of Chemistry, University of Hong Kong, Pokfulam Road, Hong Kong S.A.R., P.R. China
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26
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Monti S, Manet I. Supramolecular photochemistry of drugs in biomolecular environments. Chem Soc Rev 2014; 43:4051-67. [DOI: 10.1039/c3cs60402k] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We illustrate how the interaction of drugs with proteins or DNA in supramolecular complexes can influence the reactions initiated by drug absorbed photons, evidencing the differences with respect to solution.
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Affiliation(s)
- Sandra Monti
- Istituto per la Sintesi Organica e la Fotoreattività
- CNR
- 40129 Bologna, Italy
| | - Ilse Manet
- Istituto per la Sintesi Organica e la Fotoreattività
- CNR
- 40129 Bologna, Italy
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27
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Shinoda M, Isozaki T, Suzuki T. Photoreaction of Ketoprofen with Tryptophan and Tyrosine in Phosphate Buffer Solution. Photochem Photobiol 2013; 90:92-8. [PMID: 23998294 DOI: 10.1111/php.12168] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2013] [Accepted: 08/27/2013] [Indexed: 11/29/2022]
Affiliation(s)
- Mio Shinoda
- Department of Chemistry and Biological Science; Aoyama Gakuin University; Kanagawa Japan
| | - Tasuku Isozaki
- Department of Chemistry and Biological Science; Aoyama Gakuin University; Kanagawa Japan
| | - Tadashi Suzuki
- Department of Chemistry and Biological Science; Aoyama Gakuin University; Kanagawa Japan
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28
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Su T, Ma J, Wong N, Phillips DL. Time-resolved spectroscopic characterization of a novel photodecarboxylation reaction mediated by homolysis of a carbon α-bond in flurbiprofen. J Phys Chem B 2013; 117:8347-59. [PMID: 23750456 DOI: 10.1021/jp403053f] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Flurbiprofen (Fp), a nonsteroidal anti-inflammatory drug (NSAID) currently in use for arthritis pain relief and in clinical trials for metastatic prostate cancer, can induce photosensitization and phototoxicity upon exposure to sunlight. The mechanisms responsible for Fp phototoxicity are poorly understood and deserve investigation. In this study, the photodecarboxylation reaction of Fp, which has been assumed to underpin its photoinduced side effects, was explored by femtosecond transient absorption (fs-TA), nanosecond transient absorption (ns-TA), and nanosecond time-resolved resonance Raman (ns-TR(3)) spectroscopic techniques in pure acetonitrile (MeCN) solvent. Density functional theory (DFT) calculations were also performed to facilitate the assignments of transient species. The resonance Raman and DFT calculation results reveal that the neutral form of Fp was the predominant species present in MeCN. Analysis of the ultraviolet/visible absorption spectrum and results from TD-DFT calculations indicate that the second excited singlet (S2) can be excited by 266 nm light. Due to its intrinsic instability, S2 rapidly underwent internal conversion (IC) to decay to the lowest lying excited singlet (S1), which was observed in the fs-TA spectra at very early delay times. Intriguingly, three distinct pathways for S1 decay seem to coexist. Specifically, other than fluorescence emission back to the ground state and transformation to the lowest triplet state T1 through intersystem crossing (ISC), the homolysis of the carbon α-bond decarboxylation reaction proceeded simultaneously to give rise to two radical species, one being carboxyl and another being the residual, denoted as FpR. The coexistence of the triplet Fp (T1) and FpR species was verified by means of TR(3) spectra along with ns-TA spectra. As a consequence of its apparent high reactivity, the FpR intermediate was observed to undergo oxidation under oxygen-saturated conditions to yield another radical species, denoted as FOR, which subsequently underwent intramolecular hydrogen transfer (IHT) and dehydroxylation (DHO) to form a final product, which could react with the carboxyl from the decarboxylation reaction to generate a minor final product. TD-DFT and transient state (TS) calculations for predicting the absorption bands and activation energies of the transient species produced in the photodecarboxylation reaction have provided valuable mechanistic insights for the assignment of the intermediate species observed in the time-resolved spectroscopy experiments reported here. The results of the time-resolved spectroscopy experiments and DFT calculations were used to elucidate the reaction mechanisms and intermediates involved in the photochemistry of Fp.
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Affiliation(s)
- Tao Su
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, PR China
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29
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Li MD, Su T, Ma J, Liu M, Liu H, Li X, Phillips DL. Phototriggered Release of a Leaving Group in Ketoprofen Derivatives via a Benzylic Carbanion Pathway, But not via a Biradical Pathway. Chemistry 2013; 19:11241-50. [DOI: 10.1002/chem.201300285] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Indexed: 11/09/2022]
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30
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Su T, Ma J, Li MD, Guan X, Yu L, Phillips DL. Time-Resolved Spectroscopic Study of the Photochemistry of Tiaprofenic Acid in a Neutral Phosphate Buffered Aqueous Solution from Femtoseconds to Final Products. J Phys Chem B 2013; 117:811-24. [DOI: 10.1021/jp310315f] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Tao Su
- Department
of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P.R. China
| | - Jiani Ma
- Department
of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P.R. China
| | - Ming-De Li
- Department
of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P.R. China
| | - Xiangguo Guan
- Department
of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P.R. China
| | - Lihong Yu
- Department
of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P.R. China
| | - David Lee Phillips
- Department
of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P.R. China
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31
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Li MD, Ma J, Su T, Liu M, Phillips DL. A time-resolved spectroscopy and density functional theory study of the solvent dependent photochemistry of fenofibric acid. Phys Chem Chem Phys 2013; 15:1557-68. [DOI: 10.1039/c2cp41739a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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32
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Ma J, Su T, Li MD, Du W, Huang J, Guan X, Phillips DL. How and When Does an Unusual and Efficient Photoredox Reaction of 2-(1-Hydroxyethyl) 9,10-Anthraquinone Occur? A Combined Time-Resolved Spectroscopic and DFT Study. J Am Chem Soc 2012; 134:14858-68. [DOI: 10.1021/ja304441n] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jiani Ma
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong S.A.R., P. R.
China
| | - Tao Su
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong S.A.R., P. R.
China
| | - Ming-De Li
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong S.A.R., P. R.
China
| | - Wei Du
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong S.A.R., P. R.
China
| | - Jinqing Huang
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong S.A.R., P. R.
China
| | - Xiangguo Guan
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong S.A.R., P. R.
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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