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Xu J, Dai CM, Xu X, Jian J. Structural and spectroscopic characterization of large boron heterocyclic radicals: Matrix infrared spectroscopy and quantum chemical calculations. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2024; 305:123539. [PMID: 37857070 DOI: 10.1016/j.saa.2023.123539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 10/08/2023] [Accepted: 10/14/2023] [Indexed: 10/21/2023]
Abstract
Six boron heterocyclic radicals with different conformations or configurations were synthesized in solid neon and identified by matrix isolation infrared spectroscopy as well as quantum-chemical calculations. The ground-state boron atom selectively attacks the C = C bond of cycloheptene forming η2 (1,2)-BC7H12 complex (A), which contains a chair conformation and a boat conformation. Species A isomerizes to the 2,3,4,5,6,7-hexahydroborocine radical (B), which involves an eight-membered boron heterocyclic ring and also has two isomers observed. The 1-(prop-1-en-1-yl)-2,3,4-dihydro borole radical (C) with E-configuration and Z-configuration is generated as the final product under UV light irradiation through ring contraction reaction and the hydrogen atom transfer reaction. The observation of species A and further photo-isomerization to species C is consistent with theoretical predictions that these reactions are thermodynamically exothermic and kinetically facile. This work not only provides a possible route for future design and synthesis of corresponding borole derivatives, but also provides new insights into the structural and spectroscopic information of boron heterocyclic radicals with different conformations and configurations.
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Affiliation(s)
- Jiaping Xu
- Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou, Zhejiang 311231, China
| | - Chuan-Ming Dai
- Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou, Zhejiang 311231, China
| | - Xin Xu
- Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou, Zhejiang 311231, China
| | - Jiwen Jian
- Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou, Zhejiang 311231, China.
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Hu H, Jiang B, Zhang B, Wang R, Zhang C, Sun C, Hu B. Novel pyrazolyazoindole derivatives as photoswitches: design, synthesis, and photoswitching behavior research combined with theoretical methods. NEW J CHEM 2022. [DOI: 10.1039/d2nj03526j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Novel pyrazolyazoindole photoswitches with high to near-complete photoconversion, adjustable thermal half-lives, photochromic properties, and potential application value are developed.
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Affiliation(s)
- Haoran Hu
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China
| | - Bitao Jiang
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China
| | - Bo Zhang
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China
| | - Rong Wang
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China
| | - Chong Zhang
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China
| | - Chengguo Sun
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China
| | - Bingcheng Hu
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China
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Kumar A, Gonu S, Vijayakumar S, Ramya CB, Rajakumar B. Experimental and Computational Investigations of the Tropospheric Photooxidation Reactions of 1,1,1,3,3,3-Hexafluoro-2-Methyl-2-Propanol Initiated by OH Radicals and Cl Atoms. J Phys Chem A 2021; 125:523-535. [PMID: 33405922 DOI: 10.1021/acs.jpca.0c08130] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The gas-phase kinetics for the reactions of OH radicals and Cl atoms with 1,1,1,3,3,3-hexafluoro-2-methyl-2-propanol (HF2M2P) were measured at temperatures between 268 and 363 K using the relative rate experimental technique. Methane and acetonitrile were used as reference compounds to measure the rate coefficients of the title reactions. For the reactions of HF2M2P with OH radicals and Cl atoms, the rate coefficients were measured to be (7.07 ± 1.21) × 10-15 and (2.85 ± 0.54) × 10-14 cm3 molecule-1 s-1, respectively, at 298 K. The obtained Arrhenius expressions for the reactions of HF2M2P with OH radicals and Cl atoms are kHF2M2P + OHExp - (268 - 363 K) = (7.84 ± 0.75) × 10-14 exp [-(717 ± 59)/T] and kHF2M2P + ClExp - (268 - 363 K) = (3.21 ± 0.45) × 10-12 exp [-(1395 ± 83)/T] cm3 molecule-1 s-1. In addition to the experimental measurements, computational kinetic calculations were also performed for the title reactions at the M06-2X/MG3S//M06-2X/6-31 + G(d,p) level of theory using advanced methods such as the canonical variational transition-state theory coupled with small curvature tunneling corrections at temperatures between 200 and 400 K. Theoretical calculations reveal that the H-abstraction from the CH3 group is a more favorable reaction channel than that from the OH group. Thermochemistry, branching ratios, cumulative atmospheric lifetime, global warming potential, acidification potential, and photochemical ozone creation potential of HF2M2P were calculated in the present investigation.
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Affiliation(s)
- Avinash Kumar
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India
| | - Srinivasulu Gonu
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India
| | - S Vijayakumar
- Department of Applied Chemistry, Samrat Ashok Technological Institute, Vidisha 464001, Madhya Pradesh, India
| | - C B Ramya
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India
| | - B Rajakumar
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India
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Kumar A, Rajakumar B. Kinetic and Mechanistic Investigation for the Gas-Phase Tropospheric Photo-oxidation Reactions of 2,2,2-Trifluoroethyl Acrylate with OH Radicals and Cl Atoms. J Phys Chem A 2020; 124:2335-2351. [PMID: 32146806 DOI: 10.1021/acs.jpca.9b10009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The photo-oxidation of 2,2,2-trifluoroethyl acrylate (TFEA) (CH2CHC(O)OCH2CF3) initiated by OH radicals and Cl atoms was investigated in tropospheric conditions using both experimental and computational methods. The kinetic measurements were carried out in the temperature range of 268-363 K using the relative rate method. The rate coefficients for the reaction of OH radicals with TFEA were measured relative to diethyl ether, ethylene, and acetaldehyde. The rate coefficients for the reaction of Cl atoms with TFEA were measured relative to propylene and ethylene. The rate coefficients for the reaction of TFEA with OH radicals and Cl atoms at 298 K were experimentally measured to be kR1exp - 298 K = (1.41 ± 0.31) × 10-11 cm3 molecule-1 s-1 and kR2exp - 298 K = (2.37 ± 0.50) × 10-10 cm3 molecule-1 s-1, respectively. The deduced temperature-dependent Arrhenius expressions for the reactions of OH radicals and Cl atoms with TFEA are kR1exp - (268 - 363 K) = (9.82 ± 1.37) × 10-12 exp. [(812 ± 152)/T] cm3 molecule-1 s-1 and kR2exp - (268 - 363 K) = (1.25 ± 0.17) × 10-11 exp. [(862 ± 85)/T] cm3 molecule-1 s-1, respectively. To complement our experimental results, computational calculations were performed at CCSD(T)/cc-pVDZ//M062X/6-31+G(d,p) and CCSD(T)/cc-pVDZ//MP2/6-311+G(d,p) levels of theory, respectively, in combination with canonical variational transition-state theory (CVT) with small curvature tunneling (SCT) over the temperature range of 200-400 K. Furthermore, the degradation mechanisms initiated by OH radicals and Cl atoms were proposed for the titled reactions based on the qualitative analysis of the products in gas chromatography-mass spectrometry (GC-MS) and gas chromatography-infrared spectroscopy (GC-IR). Atmospheric implications, thermochemistry, and branching ratios for the titled reactions are discussed in detail in the paper.
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Affiliation(s)
- Avinash Kumar
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India
| | - Balla Rajakumar
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India
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Kumar A, Rajakumar B. Kinetics and Mechanistic Study for Gas Phase Tropospheric Photo-oxidation Reactions of 2,2,2-Trifluoroethyl Methacrylate with OH Radicals and Cl Atoms: An Experimental and Computational Approach. J Phys Chem A 2019; 123:10868-10884. [DOI: 10.1021/acs.jpca.9b08613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Avinash Kumar
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India
| | - B. Rajakumar
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India
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Kumar A, Rajakumar B. Gas Phase Kinetics and Mechanistic Insights for the Reactions of Cl atoms with Isopropyl Formate and Isobutyl Formate. J Phys Chem A 2019; 123:9978-9994. [DOI: 10.1021/acs.jpca.9b08410] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Avinash Kumar
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India
| | - B. Rajakumar
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India
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Cheramangalath Balan R, Rajakumar B. Cl-Atom-Initiated Atmospheric Degradation of Saturated Cyclic Hydrocarbons: Kinetic and Mechanistic Investigation. J Phys Chem A 2019; 123:7361-7373. [DOI: 10.1021/acs.jpca.9b02225] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - B. Rajakumar
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India
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Cheramangalath Balan R, Rajakumar B. Photo-Oxidation Reaction Kinetics and Mechanistics of 4-Hydroxy-2-butanone with Cl Atoms and OH Radicals in the Gas Phase. J Phys Chem A 2019; 123:4342-4353. [PMID: 31026164 DOI: 10.1021/acs.jpca.9b00995] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The temperature-dependent rate coefficients for the gas-phase reaction of 4-hydroxy-2-butanone (4H2BN) with Cl atoms and OH radicals were explored experimentally using relative rate technique and computational methods. The concentrations of the reactants as well as products were followed using gas chromatography (GC) with the flame ionization detector, GC/mass spectrometry, and GC/infrared spectroscopy as analytical techniques. Formaldehyde was obtained as the major product during the title reaction. The kinetics of 4H2BN with Cl atoms and OH radicals were measured over the temperature range of 298-363 K at 760 Torr in the N2 atmosphere using C3H8, C2H4, isopropanol, and n-propanol as reference compounds. The temperature-dependent rate coefficients for the reaction of 4H2BN with Cl atoms and OH radicals were obtained as kExpt( T) = [(1.52 ± 0.86) × 10-26] T5 exp[(2474 ± 450)/ T] cm3 molecule-1 s-1 and kexpt( T) = [(2.09 ± 0.24) × 10-12] exp[-(409 ± 15)/ T] cm3 molecule-1 s-1, respectively. Theoretical calculations were carried out at the M062X/6-31G(d,p) and M06-2X/6-31+G(d,p) level of theories, and the rate coefficients for H abstraction reactions were evaluated using the canonical variational transition state theory with the inclusion of small-curvature tunneling correction over the temperature range of 200-400 K. The rate coefficients obtained over the studied temperature range were used to fit the data, and the Arrhenius expression was obtained to be kCl(Theory) (200-400 K) = (6.10 × 10-25) T4.42 exp(2397/ T) cm3 molecule-1 s-1, kOH(Theory) (200-400 K) = (1.13 × 10-19) T2.27 exp(1505/ T) cm3 molecule-1 s-1, respectively, for the reactions of Cl atoms and OH radicals with 4H2BN. The possible reaction mechanism proposed based on the obtained products for the title reaction, thermochemistry, branching ratios, and atmospheric implications and cumulative lifetime of 4H2BN were also explored in this study.
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Affiliation(s)
| | - B Rajakumar
- Department of Chemistry , Indian Institute of Technology Madras , Chennai 600036 , India
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Kumar A, Rajakumar B. Cl Atom Initiated Photo-oxidation of Mono-chlorinated Propanes To Form Carbonyl Compounds: A Kinetic and Mechanistic Approach. J Phys Chem A 2019; 123:723-741. [DOI: 10.1021/acs.jpca.8b09132] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Avinash Kumar
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India
| | - B. Rajakumar
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India
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Cheramangalath Balan R, Rajakumar B. Photo Oxidation Reaction Kinetics of Ethyl Propionate with Cl Atom and Formation of Propionic Acid. J Phys Chem A 2018; 122:8274-8285. [DOI: 10.1021/acs.jpca.8b05215] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - B. Rajakumar
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India
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Srinivasulu G, Vijayakumar S, Rajakumar B. Kinetic Investigations on the Gas Phase Reaction of 2,2,2-Trifluoroethylbutyrate with OH Radicals: An Experimental and Theoretical Study. ChemistrySelect 2018. [DOI: 10.1002/slct.201703113] [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)
- Gonu Srinivasulu
- Department of Chemistry; Indian Institute of Technology Madras; Chennai 600036 India
| | - Siripina Vijayakumar
- Department of Chemistry; Indian Institute of Technology Madras; Chennai 600036 India
| | - Balla Rajakumar
- Department of Chemistry; Indian Institute of Technology Madras; Chennai 600036 India
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