1
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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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2
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Rodríguez Aguado E, Cecilia JA, Infantes-Molina A, Talon A, Storaro L, Moretti E, Rodríguez-Castellón E. Photocatalyzed preferential oxidation of CO under simulated sunlight using Au-transition metal oxide-sepiolite catalysts. Dalton Trans 2020; 49:3946-3955. [PMID: 31958109 DOI: 10.1039/c9dt04243a] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
In the present study a series of Au-transition metal oxides supported on a clay mineral such as sepiolite were tested in the preferential oxidation of CO in an excess of H2 under simulated solar light irradiation and in the absence of light, at 30 °C and atmospheric pressure. Transition metal oxides (ZnO, Fe2O3, NiO, MnO2, and Co3O4) were dispersed over the sepiolite surface where, subsequently, Au nanoparticles with an average particle size between 2 and 3 nm were successfully deposited-precipitated. The obtained photocatalysts were characterized by XRD, XRF, DRUV-Vis, N2 adsorption-desorption and HRTEM in order to evaluate the optical, structural and chemical properties of the prepared samples. Despite the low amount of gold (nominal 1.0 wt%), the catalysts exhibited an outstanding behavior under light irradiation, with reaction rates between 4.5 and 5.2 mmol COox gcat-1 h-1 for the Au-NiSep, Au-CoSep and Au-ZnSep samples. These photocatalysts exhibited a high dispersion of the respective transition metal oxides over the sepiolite support and the presence of low-coordinated hemispherical gold nanoparticles. The superior photocatalytic efficiency of these samples was ascribed to the reduction of the electron-hole pair recombination of photogenerated charge carriers by the excitation of the localized surface plasmon resonance of the Au nanoparticles. The BET surface area and the gold particle size seemed to be relevant factors affecting the catalytic performance.
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Affiliation(s)
- Elena Rodríguez Aguado
- Departamento de Química Inorgánica, Cristalografía y Mineralogía, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain.
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3
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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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4
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Mohmeyer A, Schäfer M, Schaate A, Locmelis S, Schneider AM, Behrens P. Inside/Outside: Post-Synthetic Modification of the Zr-Benzophenonedicarboxylate Metal-Organic Framework. Chemistry 2020; 26:2222-2232. [PMID: 32017252 PMCID: PMC7065178 DOI: 10.1002/chem.201903630] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 11/25/2019] [Indexed: 11/30/2022]
Abstract
The Zr‐based metal–organic framework, Zr‐bzpdc‐MOF, contains the photoreactive linker molecule benzophenone‐4,4′‐dicarboxylate (bzpdc) which imparts the possibility for photochemical post‐synthetic modification. Upon irradiation with UV light, the keto group of the benzophenone moiety will react with nearly every C−H bond‐containing molecule. Within this paper, we further explore the photochemical reactivity of the Zr‐bzpdc‐MOF, especially with regard to which restrictions govern internal versus external reactions. We show that apart from reactions with C−H bond‐containing molecules, the MOF reacts also with water. By studying the reactivity versus linear alcohols we find a clear delineation in that shorter alcohol molecules (up to butanol as a borderline case) react with photoexcited keto groups throughout the whole crystals whereas longer ones react only with surface‐standing keto groups. In addition, we show that with the alkanes n‐butane to n‐octane, the reaction is restricted to the outer surface. We hypothesize that the reactivity of the Zr‐bzpdc‐MOF versus different reagents depends on the accessibility of the pore system which in turn depends mainly on the size of the reagents and on their polarity. The possibility to direct the post‐synthetic modification of the Zr‐bzpdc‐MOF (selective modification of the whole pore system versus surface modification) gives additional degrees of freedom in the design of this metal–organic framework for shaping and for applications.
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Affiliation(s)
- Alexander Mohmeyer
- Institute for Inorganic Chemistry, Leibniz University Hannover, Callinstr. 9, 30167, Hannover, Germany
| | - Malte Schäfer
- Institute for Inorganic Chemistry, Leibniz University Hannover, Callinstr. 9, 30167, Hannover, Germany
| | - Andreas Schaate
- Institute for Inorganic Chemistry, Leibniz University Hannover, Callinstr. 9, 30167, Hannover, Germany.,Cluster of Excellence PhoenixD, (Photonics, Optics, and Engineering-Innovation Across Disciplines), Hannover, Germany
| | - Sonja Locmelis
- Institute for Inorganic Chemistry, Leibniz University Hannover, Callinstr. 9, 30167, Hannover, Germany
| | - Andreas M Schneider
- Institute for Inorganic Chemistry, Leibniz University Hannover, Callinstr. 9, 30167, Hannover, Germany.,Cluster of Excellence PhoenixD, (Photonics, Optics, and Engineering-Innovation Across Disciplines), Hannover, Germany
| | - Peter Behrens
- Institute for Inorganic Chemistry, Leibniz University Hannover, Callinstr. 9, 30167, Hannover, Germany.,Cluster of Excellence PhoenixD, (Photonics, Optics, and Engineering-Innovation Across Disciplines), Hannover, Germany
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5
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Liao S, Liu J, Yan L, Liu Q, Chen G, Ma L. 2-Bromoanthraquinone as a highly efficient photocatalyst for the oxidation of sec-aromatic alcohols: experimental and DFT study. RSC Adv 2020; 10:37014-37022. [PMID: 35521235 PMCID: PMC9057153 DOI: 10.1039/d0ra06414a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 08/18/2020] [Indexed: 11/21/2022] Open
Abstract
Anthraquinones are recognized as high efficiency photocatalysts which can perform various redox reactions in aqueous or organic phases. We have experimentally proven that 2-BrAQ can undergo hydrogen transfer with an alpha-aromatic alcohol under light conditions, thereby efficiently oxidizing the aromatic alcohol to the corresponding product. The yield of 1-phenethanol to acetophenone can reach more than 96%. In subsequent catalyst screening experiments, it was found that the electronegativity of the substituent at the 2 position of the anthraquinone ring and the acidity of the solvent affect the photocatalytic activity of anthraquinones. After using various aromatic alcohol substrates, 2-BrAQ showed good conversion and selectivity for most aromatic alcohols, but showed C–C bond cleavage and low selectivity with non-α-position aromatic alcohols. In order to explore the mechanism of the redox reaction of 2-BrAQ in acetonitrile solution, the corresponding free radical reaction pathway was proposed and verified by density functional theory (DFT). Focusing on calculations for 2-BrAQ during the reaction and the first-step hydrogen transfer reaction between the 2-BrAQ triplet molecule and the 1-phenylethanol molecule, we recognized the changes that occurred during the reaction and thus have a deeper understanding of the redox reaction of anthraquinone compounds in organic systems. Anthraquinones are recognized as high efficiency photocatalysts which can perform various redox reactions in aqueous or organic phases.![]()
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Affiliation(s)
- Shengfu Liao
- Biomass Catalytic Conversion Laboratory
- Guangzhou Institute of Energy
- Chinese Academy of Sciences
- Guangzhou
- China
| | - Jianguo Liu
- Biomass Catalytic Conversion Laboratory
- Guangzhou Institute of Energy
- Chinese Academy of Sciences
- Guangzhou
- China
| | - Long Yan
- Biomass Catalytic Conversion Laboratory
- Guangzhou Institute of Energy
- Chinese Academy of Sciences
- Guangzhou
- China
| | - Qiying Liu
- Biomass Catalytic Conversion Laboratory
- Guangzhou Institute of Energy
- Chinese Academy of Sciences
- Guangzhou
- China
| | - Guanghui Chen
- Department of Chemistry
- Shantou University
- Shantou 515063
- PR China
| | - Longlong Ma
- Biomass Catalytic Conversion Laboratory
- Guangzhou Institute of Energy
- Chinese Academy of Sciences
- Guangzhou
- China
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6
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Mohmeyer A, Schaate A, Hoppe B, Schulze HA, Heinemeyer T, Behrens P. Direct grafting-from of PEDOT from a photoreactive Zr-based MOF – a novel route to electrically conductive composite materials. Chem Commun (Camb) 2019; 55:3367-3370. [DOI: 10.1039/c8cc10298h] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Photochemical modification of Zr-bzpdc-MOF with PEDOT through direct polymerization of EDOT at the MOF surface gives an electrically conductive material.
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Affiliation(s)
- Alexander Mohmeyer
- Institute for Inorganic Chemistry
- Leibniz University Hannover
- Germany
- Cluster of Excellence Hearing4all
- Leibniz University Hannover
| | - Andreas Schaate
- Institute for Inorganic Chemistry
- Leibniz University Hannover
- Germany
| | - Bastian Hoppe
- Institute for Inorganic Chemistry
- Leibniz University Hannover
- Germany
| | | | - Thea Heinemeyer
- Institute for Inorganic Chemistry
- Leibniz University Hannover
- Germany
| | - Peter Behrens
- Institute for Inorganic Chemistry
- Leibniz University Hannover
- Germany
- Cluster of Excellence Hearing4all
- Leibniz University Hannover
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7
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Duraisamy S, Priyadarshini BG. Enhancing the Optical Behavior of Glass Surface by Creation of Microstructures in Single-Step Hydrothermal Wet Etching. ChemistrySelect 2018. [DOI: 10.1002/slct.201800686] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Sivagami Duraisamy
- Department of Physics; Nanotech Research Innovation & Incubation Centre, PSG Institute of Advanced Studies, Peelamedu, Coimbatore, Tamil Nadu; India
| | - B. Geetha Priyadarshini
- Department of Physics; Nanotech Research Innovation & Incubation Centre, PSG Institute of Advanced Studies, Peelamedu, Coimbatore, Tamil Nadu; India
- Department of Physics; PSG College of Technology, Peelamedu, Coimbatore, Tamil Nadu; India
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8
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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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9
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Osváth Z, Tóth T, Iván B. Synthesis, characterization, LCST-type behavior and unprecedented heating-cooling hysteresis of poly(N-isopropylacrylamide-co-3-(trimethoxysilyl)propyl methacrylate) copolymers. POLYMER 2017. [DOI: 10.1016/j.polymer.2016.12.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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10
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Zhang X, Ma J, Li S, Li MD, Guan X, Lan X, Zhu R, Phillips DL. Ketyl Radical Formation via Proton-Coupled Electron Transfer in an Aqueous Solution versus Hydrogen Atom Transfer in Isopropanol after Photoexcitation of Aromatic Carbonyl Compounds. J Org Chem 2016; 81:5330-6. [PMID: 27266916 DOI: 10.1021/acs.joc.6b00620] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Xiting Zhang
- Department
of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
| | - Jiani Ma
- Key
Laboratory of Synthetic and Natural Functional Molecule Chemistry
of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi’an 710127, P. R. China
| | - Songbo Li
- 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
| | - Xin Lan
- Department
of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
| | - Ruixue Zhu
- 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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11
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Ravi Kumar V, Verma C, Umapathy S. Molecular dynamics and simulations study on the vibrational and electronic solvatochromism of benzophenone. J Chem Phys 2016; 144:064302. [DOI: 10.1063/1.4941058] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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12
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Huang J, Ma J, Li M, Liu M, Zhang X, Phillips DL. How Does the C–Halogen Bond Break in the Photosubstitution Reaction of 3-Fluorobenzophenone in Acidic Aqueous Solutions? J Org Chem 2015; 80:9425-36. [DOI: 10.1021/acs.joc.5b01308] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jinqing Huang
- Department
of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, People’s Republic of China
| | - Jiani Ma
- Department
of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, People’s Republic of China
- Key
Laboratory of Synthetic and Natural Functional Molecule Chemistry
of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi’an 710127, People’s Republic of China
| | - Mingde Li
- Department
of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, People’s Republic of China
| | - Mingyue Liu
- Department
of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, People’s Republic of China
| | - Xiting Zhang
- Department
of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, People’s Republic of China
| | - David Lee Phillips
- Department
of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, People’s Republic of China
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13
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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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14
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Elenewski JE, Hackett JC. Solvatochromism and the solvation structure of benzophenone. J Chem Phys 2014; 138:224308. [PMID: 23781796 DOI: 10.1063/1.4809529] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Many complex molecular phenomena, including macromolecular association, protein folding, and chemical reactivity, are determined by the nuances of their electrostatic landscapes. The measurement of such electrostatic effects is nonetheless difficult, and is typically accomplished by exploiting a spectroscopic probe within the system of interest, such as through the vibrational Stark effect. Raman spectroscopy and solvatochromism afford an alternative to this method, circumventing the limitations of infrared spectroscopy, providing a lower detection limit, and permitting measurement in a native chemical environment. To explore this possibility, the solvatochromism of the C=O and aromatic C-H stretching modes of benzophenone are investigated using Raman spectroscopy. In conjunction with density functional theory calculations, these observations are sufficient to determine the probe electrostatic environment as well as contributions from halogen and hydrogen bonding. Further analysis using a detailed Kubo-Anderson lineshape model permits the detailed assignment of distinct hydrogen bonding configurations for water in the benzophenone solvation shell. These observations reinforce the use of benzophenone as an effective electrostatic probe for complex chemical systems.
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Affiliation(s)
- Justin E Elenewski
- Department of Physiology and Biophysics and The Massey Cancer Center, School of Medicine, Virginia Commonwealth University, 401 College Street, Richmond, Virginia 23219-1540, USA
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15
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Chen X, Zhang Q, Xu Y, Fang W, Phillips DL. Water-Assisted Self-Photoredox of 3-(Hydroxymethyl)benzophenone: An Unusual Photochemistry Reaction in Aqueous Solution. J Org Chem 2013; 78:5677-84. [DOI: 10.1021/jo4008783] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Xuebo Chen
- Key Laboratory of Theoretical and Computational Photochemistry of
Ministry of Education, Department of Chemistry, Beijing Normal University, Xin-wai-da-jie No. 19, Beijing 100875,
People’s Republic of China
| | - Qiangqiang Zhang
- Key Laboratory of Theoretical and Computational Photochemistry of
Ministry of Education, Department of Chemistry, Beijing Normal University, Xin-wai-da-jie No. 19, Beijing 100875,
People’s Republic of China
| | - Yanchang Xu
- Key Laboratory of Theoretical and Computational Photochemistry of
Ministry of Education, Department of Chemistry, Beijing Normal University, Xin-wai-da-jie No. 19, Beijing 100875,
People’s Republic of China
| | - Weihai Fang
- Key Laboratory of Theoretical and Computational Photochemistry of
Ministry of Education, Department of Chemistry, Beijing Normal University, Xin-wai-da-jie No. 19, Beijing 100875,
People’s Republic of China
| | - David Lee Phillips
- Department of Chemistry, The University of Hong Kong, Hong Kong, People’s Republic of China
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16
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Ma J, Su T, Li MD, Zhang X, Huang J, Phillips DL. meta versus para substitution: how does C-H activation in a methyl group occur in 3-methylbenzophenone but does not take place in 4-methylbenzophenone? J Org Chem 2013; 78:4867-78. [PMID: 23586524 DOI: 10.1021/jo400413t] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The photophysical and photochemical reactions of 3-methylbenzophenone (3-MeBP) and 4-methylbenzophenone (4-MeBP) were investigated using femtosecond transient absorption (fs-TA) and nanosecond time-resolved resonance Raman (ns-TR(3)) spectroscopy and density functional theory (DFT) calculations. 3-MeBP and 4-MeBP were observed to behave similarly to their parent compound benzophenone (BP) in acetonitrile and isopropyl alcohol solvents. However, in acidic aqueous solutions, an unusual acid-catalyzed proton exchange reaction (denoted the m-methyl activation) of 3-MeBP (with a maximum efficiency at pH 0) is detected to compete with a photohydration reaction. In contrast, only the photohydration reaction was observed for 4-MeBP under the acidic pH conditions investigated. How the m-methyl activation takes place after photolysis of 3-MeBP in acid aqueous solutions is briefly discussed and compared to related photochemistry of other meta-substituted aromatic carbonyl compounds.
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Affiliation(s)
- Jiani Ma
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, People's Republic of China
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17
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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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18
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Li MD, Ma J, Su T, Liu M, Yu L, Phillips DL. Direct Observation of Triplet State Mediated Decarboxylation of the Neutral and Anion Forms of Ketoprofen in Water-Rich, Acidic, and PBS Solutions. J Phys Chem B 2012; 116:5882-7. [DOI: 10.1021/jp301555e] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [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, People’s
Republic of China
| | - Jiani Ma
- Department
of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, People’s
Republic of China
| | - Tao Su
- Department
of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, People’s
Republic of China
| | - Mingyue Liu
- Department
of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, People’s
Republic of China
| | - Lihong Yu
- Department
of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, People’s
Republic of China
| | - David Lee Phillips
- Department
of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, People’s
Republic of China
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19
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Li MD, Yeung CS, Guan X, Ma J, Li W, Ma C, Phillips DL. Water- and Acid-Mediated Excited-State Intramolecular Proton Transfer and Decarboxylation Reactions of Ketoprofen in Water-Rich and Acidic Aqueous Solutions. Chemistry 2011; 17:10935-50. [DOI: 10.1002/chem.201003297] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2010] [Indexed: 11/10/2022]
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20
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Ma J, Li MD, Phillips DL, Wan P. Reaction Mechanisms and Structural Characterization of the Reactive Intermediates Observed after the Photolysis of 3-(Hydroxymethyl)benzophenone in Acetonitrile, 2-Propanol, and Neutral and Acidic Aqueous Solutions. J Org Chem 2011; 76:3710-9. [DOI: 10.1021/jo1024249] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jiani Ma
- 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
| | - David Lee Phillips
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong S.A.R., P. R. China
| | - Peter Wan
- Department of Chemistry, Box 3065, University of Victoria, Victoria, British Columbia, Canada V8W 3V6
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21
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Schneider MH, Tran Y, Tabeling P. Benzophenone absorption and diffusion in poly(dimethylsiloxane) and its role in graft photo-polymerization for surface modification. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:1232-40. [PMID: 21207954 DOI: 10.1021/la103345k] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Following the great success of traditional microfluidic devices across many disciplines, a new class of microfluidic systems emerged in recent years, which features finely tuned, localized surface modifications within the microstructures in order to keep up with the demand for devices of ever increasing complexity (lab on chip, assay on chip, etc.). Graft photopolymerization has become a powerful tool for such localized surface modifications particularly in combination with poly(dimethylsiloxane) (PDMS) devices, as it is compatible with many functional monomers and allows for high spatial resolution. However, application within enclosed PDMS microstructures and in particular well-controlled surface-directed polymerization remains challenging. Detailed understanding of the interaction between photoinitiator, benzophenone (BP), and polymer matrix is needed. We have developed a visualization technique, which allows for observation of reacted BP in situ within the PDMS matrix. We present a detailed study on solvent-driven BP diffusion providing results essential to successful surface treatment. We also identified and investigated photoinitiator inhibition by oxygen and provide appropriate mitigation strategies.
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Affiliation(s)
- Marc H Schneider
- Microfluidique, MEMS & Nanostructures, UMR 7083 Gulliver CNRS-ESPCI, Paris, France
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22
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Unravelling the Reaction Mechanism for the Fast Photocyclisation of 2-Benzoylpyridine in Aqueous Solvent by Time-Resolved Spectroscopy and Density Functional Theory Calculations. Chemistry 2010; 16:6961-72. [DOI: 10.1002/chem.200903073] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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23
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Li MD, Du Y, Chuang YP, Xue J, Phillips DL. Water concentration dependent photochemistry of ketoprofen in aqueous solutions. Phys Chem Chem Phys 2010; 12:4800-8. [DOI: 10.1039/b919330h] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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24
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Li MD, Du Y, Yeung CS, Phillips DL. Time-Resolved Resonance Raman Study of the Effect of pH on the Photoreactions of 3-Benzoylpyridine in Aqueous Solution. J Phys Chem A 2009; 113:12215-24. [DOI: 10.1021/jp905984w] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ming-De Li
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
| | - Yong Du
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
| | - Chi Shun Yeung
- 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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25
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Chuang YP, Xue J, Du Y, Li M, An HY, Phillips DL. Time-Resolved Resonance Raman and Density Functional Theory Investigation of the Photochemistry of (S)-Ketoprofen. J Phys Chem B 2009; 113:10530-9. [DOI: 10.1021/jp903234m] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yung Ping Chuang
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, People’s Republic of China
| | - Jiadan Xue
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, People’s Republic of China
| | - Yong Du
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, People’s Republic of China
| | - Mingde Li
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, People’s Republic of China
| | - Hui-Ying An
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, People’s Republic of China
| | - David Lee Phillips
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, People’s Republic of China
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