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Loskutova K, Torras M, Zhao Y, Svagan AJ, Grishenkov D. Cellulose Nanofiber-Coated Perfluoropentane Droplets: Fabrication and Biocompatibility Study. Int J Nanomedicine 2023; 18:1835-1847. [PMID: 37051314 PMCID: PMC10085006 DOI: 10.2147/ijn.s397626] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Accepted: 03/10/2023] [Indexed: 04/14/2023] Open
Abstract
Purpose To study the effect of cellulose nanofiber (CNF)-shelled perfluoropentane (PFP) droplets on the cell viability of 4T1 breast cancer cells with or without the addition of non-encapsulated paclitaxel. Methods The CNF-shelled PFP droplets were produced by mixing a CNF suspension and PFP using a homogenizer. The volume size distribution and concentration of CNF-shelled PFP droplets were estimated from images taken with an optical microscope and analyzed using Fiji software and an in-house Matlab script. The thermal stability was qualitatively assessed by comparing the size distribution and concentration of CNF-shelled PFP droplets at room temperature (~22°) and 37°C. The cell viability of 4T1 cells was measured using a 3-[4,5-dimethylthiazol-2yl]-2,5-diphenyltetrazolium bromide (MTT) assay. Additionally, a hemolysis assay was performed to assess blood compatibility of CNF-shelled PFP droplets. Results The droplet diameter and concentration of CNF-shelled PFP droplets decreased after 48 hours at both room temperature and 37°C. In addition, the decrease in concentration was more significant at 37°C, from 3.50 ± 0.64×106 droplets/mL to 1.94 ± 0.10×106 droplets/mL, than at room temperature, from 3.65 ± 0.29×106 droplets/mL to 2.56 ± 0.22×106 droplets/mL. The 4T1 cell viability decreased with increased exposure time and concentration of paclitaxel, but it was not affected by the presence of CNF-shelled PFP droplets. No hemolysis was observed at any concentration of CNF-shelled PFP droplets. Conclusion CNF-shelled PFP droplets have the potential to be applied as drug carriers in ultrasound-mediated therapy.
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Affiliation(s)
- Ksenia Loskutova
- Department of Biomedical Engineering and Health Systems, KTH Royal Institute of Technology, Huddinge, SE-141 57, Sweden
- Correspondence: Ksenia Loskutova, Department of Biomedical Engineering and Health Systems, KTH Royal Institute of Technology, Hälsovägen 11C, Huddinge, SE-14157, Sweden, Tel +46 707 26 76 77, Email
| | - Mar Torras
- Department of Biomedical Engineering and Health Systems, KTH Royal Institute of Technology, Huddinge, SE-141 57, Sweden
| | - Ying Zhao
- Department of Laboratory Medicine, Karolinska Institute, Huddinge, SE-141 57, Sweden
| | - Anna J Svagan
- Department of Fibre and Polymer Technology, KTH Royal Institute of Technology, Stockholm, SE-100 44, Sweden
| | - Dmitry Grishenkov
- Department of Biomedical Engineering and Health Systems, KTH Royal Institute of Technology, Huddinge, SE-141 57, Sweden
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Novel Magnetic Elastic Phase-Change Nanodroplets as Dual Mode Contrast Agent for Ultrasound and Magnetic Resonance Imaging. Polymers (Basel) 2022; 14:polym14142915. [PMID: 35890691 PMCID: PMC9318938 DOI: 10.3390/polym14142915] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Revised: 06/05/2022] [Accepted: 06/08/2022] [Indexed: 01/25/2023] Open
Abstract
Recently, dual-mode imaging systems merging magnetic resonance imaging (MRI) and ultrasound (US) have been developed. Designing a dual-mode contrast agent is complex due to different mechanisms of enhancement. Herein, we describe novel phase change nanodroplets (PCNDs) with perfluoropentane encapsulated in a pre-polyglycerol sebacate (pre-PGS) shell loaded with polyethylene glycol (PEG)-coated iron oxide nanoparticles as having a dual-mode contrast agent effect. Iron oxide nanoparticles were prepared via the chemical co-precipitation method and PCNDs were prepared via the solvent displacement technique. PCNDs showed excellent enhancement in the in vitro US much more than Sonovue® microbubbles. Furthermore, they caused a susceptibility effect resulting in a reduction of signal intensity on MRI. An increase in the concentration of nanoparticles caused an increase in the MR contrast effect but a reduction in US intensity. The concentration of nanoparticles in a shell of PCNDs was optimized to obtain a dual-mode contrast effect. Biocompatibility, hemocompatibility, and immunogenicity assays showed that PCNDs were safe and non-immunogenic. Another finding was the dual-mode potential of unloaded PCNDs as T1 MR and US contrast agents. Results suggest the excellent potential of these PCNDs for use as dual-mode contrast agents for both MRI and US.
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Infrared absorption cross section and radiative forcing efficiency features of four hydrofluoropolyethers: Performance of some DFT functionals. COMPUT THEOR CHEM 2022. [DOI: 10.1016/j.comptc.2022.113798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Holtomo O, Rhyman L, Nsangou M, Ramasami P, Motapon O. Reaction of •OH with CHCl=CH-CHF2 and its atmospheric implication for future environmental-friendly refrigerant. PURE APPL CHEM 2021. [DOI: 10.1515/pac-2021-0116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
In order to understand the atmospheric implication of the chlorinated hydrofluoroolefin (HFO), the geometrical structures and the IR absorption cross sections of the stereoisomers 1-chloro-3,3-difluoropropene were studied using the B3LYP/6-31G(3df) and M06-2X/6-31G(3df) methods in the gas phase. The cis-trans isomerization was assessed using the M06-2X/6-311++G(3df,p)//6-31+G(3df,p) method. The latter method was also employed for thermochemistry and the rate coefficients of the reactions of •OH with the cis- and trans-isomers in the temperature ranging from 200 to 400 K. The computational method CCSD/cc-pVTZ//M06-2X/6-31+G(3df,p) was used to benchmark the rate coefficients. It turns out that, the trans-isomer is more stable than cis-isomer and the trans- to cis-isomerization is thermodynamically unfavorable. The rate coefficient follows the Gaussian law with respect to the inverse of temperature. At the global temperature of stratosphere, the calculated rate coefficients served to estimate the atmospheric lifetime along with the photochemical ozone creation potential (POCP). This yielded lifetimes of 4.31 and 7.31 days and POCPs of 3.80 and 2.23 for the cis- and trans-isomer, respectively. The radiative forcing efficiencies gave 0.0082 and 0.0152 W m−2 ppb−1 for the cis- and trans-isomer, respectively. The global warming potential approached zero for both stereoisomers at 20, 100, and 500 years time horizons.
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Affiliation(s)
- Olivier Holtomo
- Department of Physics , Faculty of Science, University of Bamenda , Bambili P.O. Box 39 , Cameroon
- Department of Physics , Faculty of Science, University of Maroua , Maroua P.O. Box 814 , Cameroon
| | - Lydia Rhyman
- Department of Chemistry , Computational Chemistry Group, Faculty of Science, University of Mauritius , Réduit 80837 Mauritius
- Department of Chemical Sciences , Centre for Natural Product Research, University of Johannesburg , Doornfontein , Johannesburg 2028 , South Africa
| | - Mama Nsangou
- Department of Physics , Higher Teacher's Training College, University of Maroua , Maroua P.O. Box 46 , Cameroon
- Department of Physics , Faculty of Science, University of Ngaoundéré , Ngaoundéré P.O. Box 454 , Cameroon
| | - Ponnadurai Ramasami
- Department of Chemistry , Computational Chemistry Group, Faculty of Science, University of Mauritius , Réduit 80837 Mauritius
- Department of Chemical Sciences , Centre for Natural Product Research, University of Johannesburg , Doornfontein , Johannesburg 2028 , South Africa
| | - Ousmanou Motapon
- Department of Physics , Faculty of Science, University of Maroua , Maroua P.O. Box 814 , Cameroon
- Laboratory of Fundamental Physics, Faculty of Science, University of Douala , Douala P.O. Box 24157 , Cameroon
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Theoretical investigations on the OH radical mediated kinetics of cis- and trans-CH3CF=CHF and CH3CH=CF2 over temperature range of 200-400K. J Fluor Chem 2021. [DOI: 10.1016/j.jfluchem.2021.109884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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6
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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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Hodnebrog Ø, Aamaas B, Fuglestvedt JS, Marston G, Myhre G, Nielsen CJ, Sandstad M, Shine KP, Wallington TJ. Updated Global Warming Potentials and Radiative Efficiencies of Halocarbons and Other Weak Atmospheric Absorbers. REVIEWS OF GEOPHYSICS (WASHINGTON, D.C. : 1985) 2020; 58:e2019RG000691. [PMID: 33015672 PMCID: PMC7518032 DOI: 10.1029/2019rg000691] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 06/26/2020] [Accepted: 07/06/2020] [Indexed: 05/10/2023]
Abstract
Human activity has led to increased atmospheric concentrations of many gases, including halocarbons, and may lead to emissions of many more gases. Many of these gases are, on a per molecule basis, powerful greenhouse gases, although at present-day concentrations their climate effect is in the so-called weak limit (i.e., their effect scales linearly with concentration). We published a comprehensive review of the radiative efficiencies (RE) and global warming potentials (GWP) for around 200 such compounds in 2013 (Hodnebrog et al., 2013, https://doi.org/10.1002/rog.20013). Here we present updated RE and GWP values for compounds where experimental infrared absorption spectra are available. Updated numbers are based on a revised "Pinnock curve", which gives RE as a function of wave number, and now also accounts for stratospheric temperature adjustment (Shine & Myhre, 2020, https://doi.org/10.1029/2019MS001951). Further updates include the implementation of around 500 absorption spectra additional to those in the 2013 review and new atmospheric lifetimes from the literature (mainly from WMO (2019)). In total, values for 60 of the compounds previously assessed are based on additional absorption spectra, and 42 compounds have REs which differ by >10% from our previous assessment. New RE calculations are presented for more than 400 compounds in addition to the previously assessed compounds, and GWP calculations are presented for a total of around 250 compounds. Present-day radiative forcing due to halocarbons and other weak absorbers is 0.38 [0.33-0.43] W m-2, compared to 0.36 [0.32-0.40] W m-2 in IPCC AR5 (Myhre et al., 2013, https://doi.org/10.1017/CBO9781107415324.018), which is about 18% of the current CO2 forcing.
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Affiliation(s)
- Ø Hodnebrog
- Center for International Climate Research (CICERO) Oslo Norway
| | - B Aamaas
- Center for International Climate Research (CICERO) Oslo Norway
| | - J S Fuglestvedt
- Center for International Climate Research (CICERO) Oslo Norway
| | - G Marston
- Vice-Chancellor's Office Northumbria University Newcastle UK
| | - G Myhre
- Center for International Climate Research (CICERO) Oslo Norway
| | - C J Nielsen
- Department of Chemistry University of Oslo Oslo Norway
| | - M Sandstad
- Center for International Climate Research (CICERO) Oslo Norway
| | - K P Shine
- Department of Meteorology University of Reading Reading UK
| | - T J Wallington
- Research and Advanced Eng. Ford Motor Company Dearborn MI USA
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Kwiatkowski CF, Andrews DQ, Birnbaum LS, Bruton TA, DeWitt JC, Knappe DRU, Maffini MV, Miller MF, Pelch KE, Reade A, Soehl A, Trier X, Venier M, Wagner CC, Wang Z, Blum A. Scientific Basis for Managing PFAS as a Chemical Class. ENVIRONMENTAL SCIENCE & TECHNOLOGY LETTERS 2020; 7:532-543. [PMID: 34307722 PMCID: PMC8297807 DOI: 10.1021/acs.estlett.0c00255] [Citation(s) in RCA: 209] [Impact Index Per Article: 52.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
This commentary presents a scientific basis for managing as one chemical class the thousands of chemicals known as PFAS (per- and polyfluoroalkyl substances). The class includes perfluoroalkyl acids, perfluoroalkylether acids, and their precursors; fluoropolymers and perfluoropolyethers; and other PFAS. The basis for the class approach is presented in relation to their physicochemical, environmental, and toxicological properties. Specifically, the high persistence, accumulation potential, and/or hazards (known and potential) of PFAS studied to date warrant treating all PFAS as a single class. Examples are provided of how some PFAS are being regulated and how some businesses are avoiding all PFAS in their products and purchasing decisions. We conclude with options for how governments and industry can apply the class-based approach, emphasizing the importance of eliminating non-essential uses of PFAS, and further developing safer alternatives and methods to remove existing PFAS from the environment.
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Affiliation(s)
- Carol F. Kwiatkowski
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - David Q. Andrews
- Environmental Working Group, Washington, D.C. 20009, United States
| | - Linda S. Birnbaum
- National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709, United States
| | - Thomas A. Bruton
- Green Science Policy Institute, Berkeley, California 94709, United States
| | - Jamie C. DeWitt
- Department of Pharmacology and Toxicology, Brody School of Medicine, East Carolina University, Greenville, North Carolina 27834, United States
| | - Detlef R. U. Knappe
- Department of Civil, Construction, and Environmental Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
| | | | - Mark F. Miller
- National Institute of Environmental Health Sciences and U.S. Public Health Service, Research Triangle Park, North Carolina 27709, United States
| | - Katherine E. Pelch
- School of Public Health, University of North Texas Health Science Center, Fort Worth, Texas 76126, United States
| | - Anna Reade
- Natural Resources Defense Council, San Francisco, California 94104, United States
| | - Anna Soehl
- Green Science Policy Institute, Berkeley, California 94709, United States
| | - Xenia Trier
- European Environment Agency, DK-1050 Copenhagen, Denmark
| | - Marta Venier
- O’Neill School of Public and Environmental Affairs, Indiana University, Bloomington, Indiana 47401, United States
| | - Charlotte C. Wagner
- Harvard John A. Paulson School of Engineering and Applied Science, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Zhanyun Wang
- Chair of Ecological Systems Design, Institute of Environmental Engineering, ETH Zürich, 8093 Zurich, Switzerland
| | - Arlene Blum
- Green Science Policy Institute, Berkeley, California 94709, United States; Department of Chemistry, University of California, Berkeley, California 94720, United States
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Hynniewta S, Baidya B, Chandra AK. Theoretical investigation on the kinetics of reaction of methoxyflurane (CH3OCF2CHCl2) with OH radical and its atmospheric impact. COMPUT THEOR CHEM 2020. [DOI: 10.1016/j.comptc.2020.112819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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10
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Kaipara R, Rajakumar B. Photooxidation Reactions of Ethyl 2-Methylpropionate (E2MP) and Ethyl 2,2-Dimethylpropionate (E22DMP) Initiated by OH Radicals: An Experimental and Computational Study. J Phys Chem A 2020; 124:2768-2784. [PMID: 32207979 DOI: 10.1021/acs.jpca.0c00903] [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
The relative rate (RR) technique was used for the measurement of OH-initiated photooxidation reactions of ethyl 2-methylpropionate (E2MP) and ethyl 2,2-dimethylpropionate (E22DMP) in the temperature range of 268-363 K at 760 Torr. In addition to this, the thermodynamic and kinetic parameters for the title reactions were theoretically investigated using CCSD(T)/cc-pVTZ//M06-2X/6-311++G(2d,2p) level of theory in the temperature range of 200-400 K using canonical variational transition state theory (CVT) in combination with small curvature tunneling (SCT) method. The rate coefficients at (298 ± 2) K were measured to be kE2MP+OH = (2.71 ± 0.79) × 10-12 cm3 molecule-1 s-1 and kE22DMP+OH = (2.58 ± 0.80) × 10-12 cm3 molecule-1 s-1. The degradation mechanisms for the title reactions were investigated in the presence of O2 using gas chromatography with mass spectrometry (GC-MS) and gas chromatography with infrared spectroscopy (GC-IR). From the recognized products, the possible product degradation mechanisms were predicted. In addition to this, the atmospheric lifetimes (ALs), lifetime-corrected radiative forcing (RF), global warming potential (GWPs) and photochemical ozone creation potentials (POCPs) were calculated to further understand the environmental impact of these molecules on the Earth's troposphere.
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Affiliation(s)
- Revathy Kaipara
- 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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Paul S, Mishra BK, Baruah SD, Deka RC, Gour NK. Atmospheric oxidation of HFE-7300 [n-C 2F 5CF(OCH 3)CF(CF 3) 2] initiated by •OH/Cl oxidants and subsequent degradation of its product radical: a DFT approach. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:907-920. [PMID: 31820248 DOI: 10.1007/s11356-019-06975-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 11/05/2019] [Indexed: 06/10/2023]
Abstract
To understand the atmospheric chemistry of hydrofluoroethers, we have studied the oxidation of a highly fluorinated compound n-C2F5CF(OCH3)CF(CF3)2 (HFE-7300) by OH/Cl oxidants. Here, we have employed M06-2X functional along with a 6-31 + G(d,p) basis set to obtain the optimized structures, various forms of energies, and different modes of frequencies for all species. We have characterized energies of all species on the potential energy surface, and it indicates that H-abstraction from n-C2F5CF(OCH3)CF(CF3)2 by Cl atom is kinetically more dominant than the H-abstraction reaction initiated by OH radical. In contrast, the calculated energy change (ΔrH°298 and ΔrG°298) results govern that OH-initiated H-abstraction reaction is highly exothermic and spontaneous compared to the Cl-initiated H-abstraction reaction. Rate constants are estimated using transition state theory as well as canonical variation transition state theory at the temperature range 200-1000 K and 1 atm pressure. The calculated rate constants of the H-abstraction channels are found to be in good agreement with the reported experimental rate constant at 298 K. Moreover, we have estimated the atmospheric lifetimes of HFE-7300 for the reaction with OH radical and Cl atom and are found to be 1.75 and 153.93 years, respectively. Additionally, the global warming potentials for HFE-7300 molecule are also estimated for 20-, 100-, and 500-year time horizons. Further, subsequent aerial oxidation of product radical (n-C2F5CF(OCH2)CF(CF3)2) in the presence of NO radical is performed, and it produced alkoxy radical via formation of peroxy radical. This alkoxy radical undergoes unimolecular decompositions via two different ways and formed n-C2F5CF(OCHO)CF(CF3)2 and n-C2F5CF(OH) CF(CF3)2 products.
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Affiliation(s)
- Subrata Paul
- Department of Chemical Sciences, Tezpur University Tezpur, Tezpur, Assam, 784028, India
| | - Bhupesh Kumar Mishra
- Department of Chemistry, D. N. Government College, Itanagar, Arunachal Pradesh, 791113, India
| | - Satyajit Dey Baruah
- Department of Chemical Sciences, Tezpur University Tezpur, Tezpur, Assam, 784028, India
| | - Ramesh Chandra Deka
- Department of Chemical Sciences, Tezpur University Tezpur, Tezpur, Assam, 784028, India
| | - Nand Kishor Gour
- Department of Chemical Sciences, Tezpur University Tezpur, Tezpur, Assam, 784028, India.
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Gupta P, Rajakumar B. Cl Atoms and OH Radicals Initiated Kinetic and Mechanistic Study on the Degradation of Propyl Butanoate under Tropospheric Conditions. J Phys Chem A 2019; 123:10976-10989. [PMID: 31789521 DOI: 10.1021/acs.jpca.9b09546] [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 reactivity of various OVOCs (mainly esters) in the troposphere leads to the generation of various organics, which in turn leads to an increase in the cloud acidity of the Earth's atmosphere. Hence, it becomes necessary to understand the mechanistic aspects of the reaction of these molecules with dominant atmospheric agents. In this study, the tropospheric degradation of one such ester, propyl butanoate (PB; CH3CH2CH2COOCH2CH2CH3) was studied with OH radicals and Cl atoms at the CCSD(T)//M06-2x/6-311+G(2d,2p) and CCSD(T)//BHandHLYP/6-311+G(2d,2p) level of theories over the studied temperature range of 200-400 K. The Arrhenius expressions obtained using the CVT/SCT/ISPE method were calculated as kPB + Cl (200-400 K) = 1.3 × 10-14 T1.3 exp[1335/T] cm3 molecule-1 s-1 and kPB + OH (200-400 K) = 1.8 × 10-26 T4.6 exp[4469/T] cm3 molecule-1 s-1. The obtained kinetics was also well validated against the SAR (structure-activity relationship)-based rate coefficients. The most prominent H-abstraction reaction channels were investigated for the PB + OH/Cl reaction. The abstraction of H atoms attached to the carbon atom present in the β-position to the ester (-C(O)O-) functionality was found to go via the lowest energy activation barriers for the reaction of PB toward both OH radicals and Cl atoms. The product degradation channels were also elucidated in an O2/NOx-rich environment. Moreover, to gauge the impact of the emitted PB on the troposphere, atmospheric lifetimes, radiative efficiencies, global warming potentials, and photochemical ozone creation potentials were also calculated and are included in the manuscript.
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Affiliation(s)
- Parth Gupta
- 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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14
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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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15
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Holtomo O, Motapon O, Nsangou M. DFT Study of Photochemical Properties and Radiative Forcing Efficiency Features of the Stereoisomers cis- and trans-CHCl═CH-CF 3. J Phys Chem A 2019; 123:10437-10445. [PMID: 31697499 DOI: 10.1021/acs.jpca.9b08089] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The accurate assessment of radiative forcing efficiency (RFE) of a greenhouse gas is based on the precise knowledge of its structure and infrared absorption spectrum. The present work investigates the UV-vis absorption spectra and IR absorption spectra that are used for the determination of RFE of the short-lived compounds, cis- and trans-CHCl═CHCF3 (CTFP). These investigations were carried out with six different density functional theory (DFT) methods B3LYP, CAM-B3LYP, M06, M06-2X, TPSS0, and ωB97X-D associated to the basis set 6-31G(3df). Therefrom, the relative populations of the two states cis and trans for temperatures over the range 220-370 K at 1 atm and along the atmospheric altitude were assessed. It turns out that trans-CTFP is the abundant component between the two states. This review reveals that B3LYP and M06 reproduce well the experimental results of UV-vis spectra of trans-CTFP. As for cis-CTFP, EOM-CCSD is not well fitted by DFT methods. The cis- to trans-CTFP isomerization leads to the red shift for DFT methods and to the blue shift in regard to EOM-CCSD and experimental results. The IR absorption spectra are well fitted by B3LYP over the range 500-1600 cm-1 and TPSS0 over 1300-2000 cm-1 for both stereoisomers. Moreover, the root-mean-square errors (RMSEs) of frequencies from experimental data are lower for B3LYP and TPSS0 for both systems. The computed IR absorption band strengths over 500-2000 cm-1 for cis- and over 600-1800 cm-1 for trans-CTFP are consistent with the experiment. The relevant descriptor RFEs of the climate effect were calculated using a narrow band model for a constant vertical profile and then corrected with a lifetime factor for different computational methods. The computed values correlate well with the experimental results for both stereoisomers except M06-2X and TPSS0. It is worth noting that, for both systems, the intense radiative forcing spectra are located at frequencies ranging in 1000-1200 cm-1. The lower forcings of trans-CTFP lying in the atmospheric window region 800-1000 cm-1 are greater than those of cis-CTFP. Therefore, RFE(trans-CTFP) = 1.127 RFE(cis-CTFP).
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Affiliation(s)
- Olivier Holtomo
- Department of Physics, Faculty of Science , University of Bamenda , P.O. Box 39, Bambili , Cameroon.,Department of Physics, Faculty of Science , University of Maroua , P.O. Box 814, Maroua , Cameroon
| | - Ousmanou Motapon
- Department of Physics, Faculty of Science , University of Maroua , P.O. Box 814, Maroua , Cameroon
| | - Mama Nsangou
- Department of Physics, Higher Teachers Training College , University of Maroua , P.O. Box 46, Maroua , Cameroon
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16
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Baidya B, Lily M, Chandra AK. Kinetics of Reactions of CHF
2
CF
2
CH
2
OH with Cl Atoms and CHF
2
CF
2
CHO with OH Radicals and Atmospheric Degradation Pathways of CHF
2
CF
2
CH
2
OH: A Theoretical Investigation. ChemistrySelect 2019. [DOI: 10.1002/slct.201901571] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Bidisha Baidya
- Department of ChemistryNorth-Eastern Hill University, Shillong India
| | - Makroni Lily
- Department of ChemistryNorth-Eastern Hill University, Shillong India
| | - Asit K. Chandra
- Department of ChemistryNorth-Eastern Hill University, Shillong India
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17
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Gupta P, Rajakumar B. A Dual Level Direct Dynamics Study for the Reaction of CF
2
=CHCF
3
(HFC‐
1225 zc
) and CF
2
=CHCF
2
CF
3
(HFC‐
1327 cz
) towards OH Radicals. ChemistrySelect 2019. [DOI: 10.1002/slct.201900006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Parth Gupta
- Department of ChemistryIndian Institute of Technology Madras Chennai 600036 India
| | - Balla Rajakumar
- Department of ChemistryIndian Institute of Technology Madras Chennai 600036 India
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18
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Gour NK, Rajkumari NP, Deka RC, Paul S, Deka A. Atmospheric degradation pathways and kinetics of 2,2-difluoroethanol (CHF2CH2OH) with Cl atom: A theoretical investigation. Chem Phys Lett 2019. [DOI: 10.1016/j.cplett.2018.11.063] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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19
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Paul S, Deka RC, Gour NK. Kinetics, mechanism, and global warming potentials of HFO-1234yf initiated by O 3 molecules and NO 3 radicals: insights from quantum study. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:26144-26156. [PMID: 29971745 DOI: 10.1007/s11356-018-2633-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Accepted: 06/20/2018] [Indexed: 06/08/2023]
Abstract
In the present investigation, the oxidation of HFO-1234yf (2,3,3,3-tetrafluoropropene) with O3 molecule and NO3 radical is studied by quantum chemical methods. The possible reaction pathways of the titled molecule with O3 molecule and NO3 radical are analyzed using M06-2X meta-hybrid density functional with the 6-311++G(d,p) basis set. We have further employed a series of single-point energy calculations by using a potentially high-level couple cluster method with single and double excitations, including perturbative corrections ((CCSD(T)) at the same basis set. The addition reaction of HFO-1234yf with O3 molecule is initiated by the formation of primary ozonide complex, which leads to the formation of various carbonyl compounds and Criegee intermediates. The calculated energy barriers and thermochemical parameters inferred that decomposition of C˙H2OO˙ and CF3CFO is slightly more preferred over the formation of CF3C˙FOO˙ and CH2O. Further, the NO3 radical addition at α- and β-sits of CF3CF〓CH2 molecule is analyzed in details. The individual and overall rate constants for each reaction pathways are calculated by using canonical transition state theory over the temperature range of 250-450 K. We have observed that the computed rate constants are in good agreement with the available experimental data. Atmospheric lifetimes and global warming potentials of the HFO-1234yf are also reported in this manuscript.
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Affiliation(s)
- Subrata Paul
- Department of Chemical Sciences, Tezpur University, Tezpur, Assam, 784028, India
| | - Ramesh Chandra Deka
- Department of Chemical Sciences, Tezpur University, Tezpur, Assam, 784028, India
| | - Nand Kishor Gour
- Department of Chemical Sciences, Tezpur University, Tezpur, Assam, 784028, India.
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20
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Baidya B, Lily M, Chandra AK. Theoretical Insight into the Kinetics of H-Abstraction Reaction of CHF 2
CH 2
OH with OH Radical, Atmospheric Lifetime and Global Warming Potential. ChemistrySelect 2018. [DOI: 10.1002/slct.201800491] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Bidisha Baidya
- Centre for Advanced Studies in Chemistry; North-Eastern Hill University; Shillong 793 022 India
| | - Makroni Lily
- Centre for Advanced Studies in Chemistry; North-Eastern Hill University; Shillong 793 022 India
| | - Asit K. Chandra
- Centre for Advanced Studies in Chemistry; North-Eastern Hill University; Shillong 793 022 India
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21
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Computational study on night-time reaction of 1, 1-Dichlorodimethylether (DCDME) CH3OCHCl2 with NO3 radical and the fortuity of alkoxy radical CH3OC(O )Cl2. Chem Phys Lett 2018. [DOI: 10.1016/j.cplett.2018.04.045] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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22
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Gour NK, Sarma PJ, Mishra BK, Deka RC. Quantum calculation on night-time degradation of 2-chloroethyl ethyl ether (CH3CH2OCH2CH2Cl) initiated by NO3 radical. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2017. [DOI: 10.1142/s0219633617500687] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A dual-level quantum chemical calculations have been carried out on the initiation of night-time degradation of 2-chloroethyl ethyl ether (CH3CH2OCH2CH2Cl) via H-abstraction by NO3 radical. Within the scope of density functional theory, the electronic structure of all the species involved in the titled reaction has been optimized at M06-2X functional along with 6-31[Formula: see text]G(d,p) basis set. A higher level of couple cluster CCSD(T) method in conjunction with 6-311[Formula: see text]G(d,p) basis set has been used for the refined energy of the species. All minima and saddle states involved in the reaction channel have been characterized on the potential energy surface (PES). From PES, it is confirmed that H-abstraction from methylene (–CH2–) of ethyl (CH3CH2–) part of CH3CH2OCH2CH2Cl follows the minimum energy path. The rate constants (individual and overall) of the titled reaction are obtained using Canonical Transition State Theory (CTST) over the temperature range of 250–350[Formula: see text]K. The atmospheric lifetime and radiative efficiency of the titled molecule have also been estimated, amounting to 0.23 years and 0.024 years, respectively. The Global Warming Potentials of the 2-chloroethyl ethyl ether in 20 years, 100 years and 500 years time horizon were found to be 0.13, 0.04 and 0.01, respectively.
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Affiliation(s)
- Nand Kishor Gour
- Department of Chemical Sciences, Tezpur, University Tezpur, Napaam, Assam 784 028, India
| | - Plaban Jyoti Sarma
- Department of Chemical Sciences, Tezpur, University Tezpur, Napaam, Assam 784 028, India
| | - Bhupesh Kumar Mishra
- Department of Chemistry, D. N. Govt. College, Itanagar, Arunachal Pradesh 791113, India
| | - Ramesh Chandra Deka
- Department of Chemical Sciences, Tezpur, University Tezpur, Napaam, Assam 784 028, India
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23
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Tropospheric degradation of HFE-7500[ n -C 3 F 7 CF(OCH 2 CH 3 )CF(CF 3 ) 2 ] initiated by OH radicals and Fate of alkoxy radical [ n -C 3 F 7 CF(OCH(O )CH 3 )CF(CF 3 ) 2 ]: A DFT investigation. J Fluor Chem 2017. [DOI: 10.1016/j.jfluchem.2017.09.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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24
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Antiñolo M, Bravo I, Jiménez E, Ballesteros B, Albaladejo J. Atmospheric Chemistry of E- and Z-CF3CH═CHF (HFO-1234ze): OH Reaction Kinetics as a Function of Temperature and UV and IR Absorption Cross Sections. J Phys Chem A 2017; 121:8322-8331. [DOI: 10.1021/acs.jpca.7b06174] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- María Antiñolo
- Departamento
de Química Física, Facultad de Ciencias
y Tecnologías Químicas, Universidad de Castilla-La Mancha, Avda. Camilo José Cela, 1B, 13071 Ciudad Real, Spain
- Instituto
de Investigación en Combustión y Contaminación
Atmosférica, Universidad de Castilla-La Mancha, Camino de Moledores,
s/n, 13071 Ciudad
Real, Spain
| | - Iván Bravo
- Departamento
de Química Física, Facultad de Farmacia, Universidad de Castilla-La Mancha, Campus Universitario de Albacete, 02071 Albacete, Spain
| | - Elena Jiménez
- Departamento
de Química Física, Facultad de Ciencias
y Tecnologías Químicas, Universidad de Castilla-La Mancha, Avda. Camilo José Cela, 1B, 13071 Ciudad Real, Spain
- Instituto
de Investigación en Combustión y Contaminación
Atmosférica, Universidad de Castilla-La Mancha, Camino de Moledores,
s/n, 13071 Ciudad
Real, Spain
| | - Bernabé Ballesteros
- Departamento
de Química Física, Facultad de Ciencias
y Tecnologías Químicas, Universidad de Castilla-La Mancha, Avda. Camilo José Cela, 1B, 13071 Ciudad Real, Spain
- Instituto
de Investigación en Combustión y Contaminación
Atmosférica, Universidad de Castilla-La Mancha, Camino de Moledores,
s/n, 13071 Ciudad
Real, Spain
| | - José Albaladejo
- Departamento
de Química Física, Facultad de Ciencias
y Tecnologías Químicas, Universidad de Castilla-La Mancha, Avda. Camilo José Cela, 1B, 13071 Ciudad Real, Spain
- Instituto
de Investigación en Combustión y Contaminación
Atmosférica, Universidad de Castilla-La Mancha, Camino de Moledores,
s/n, 13071 Ciudad
Real, Spain
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25
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Night-time reaction of 2-chloroethyl methyl ether (CH 3 OCH 2 CH 2 Cl) initiated by NO 3 radical: A theoretical insight. COMPUT THEOR CHEM 2017. [DOI: 10.1016/j.comptc.2017.03.042] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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26
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Lily M, Baidya B, Chandra AK. Theoretical studies on atmospheric chemistry of HFE-245mc and perfluoro-ethyl formate: Reaction with OH radicals, atmospheric fate of alkoxy radical and global warming potential. Chem Phys Lett 2017. [DOI: 10.1016/j.cplett.2016.12.037] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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27
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Rao PK, Gejji SP. Kinetics and Mechanistic Investigations of Atmospheric Oxidation of HFO-1345fz by OH Radical: Insights from Theory. J Phys Chem A 2017; 121:595-607. [DOI: 10.1021/acs.jpca.6b11312] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Pradeep Kumar Rao
- Department of Chemistry, Savitribai Phule Pune University, Pune 411007, India
| | - Shridhar P. Gejji
- Department of Chemistry, Savitribai Phule Pune University, Pune 411007, India
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28
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Betowski D, Bevington C, Allison TC. Estimation of Radiative Efficiency of Chemicals with Potentially Significant Global Warming Potential. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:790-7. [PMID: 26647007 DOI: 10.1021/acs.est.5b04154] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Halogenated chemical substances are used in a broad array of applications, and new chemical substances are continually being developed and introduced into commerce. While recent research has considerably increased our understanding of the global warming potentials (GWPs) of multiple individual chemical substances, this research inevitably lags behind the development of new chemical substances. There are currently over 200 substances known to have high GWP. Evaluation of schemes to estimate radiative efficiency (RE) based on computational chemistry are useful where no measured IR spectrum is available. This study assesses the reliability of values of RE calculated using computational chemistry techniques for 235 chemical substances against the best available values. Computed vibrational frequency data is used to estimate RE values using several Pinnock-type models, and reasonable agreement with reported values is found. Significant improvement is obtained through scaling of both vibrational frequencies and intensities. The effect of varying the computational method and basis set used to calculate the frequency data is discussed. It is found that the vibrational intensities have a strong dependence on basis set and are largely responsible for differences in computed RE values.
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Affiliation(s)
- Don Betowski
- U.S. Environmental Protection Agency, National Exposure Research Laboratory, Environmental Sciences Division, P.O. Box 93478, Las Vegas, Nevada 89193-3478, United States
| | - Charles Bevington
- U.S. Environmental Protection Agency, Office of Pollution Prevention and Toxics, Risk Assessment Division, 1200 Pennsylvania Avenue, N. W., Mail Code: 7408M, Washington, D.C. 20460, United States
| | - Thomas C Allison
- Material Measurement Laboratory, National Institute of Standards and Technology , 100 Bureau Drive, Stop 8320, Gaithersburg, Maryland 20899-8320, United States
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29
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Mishra BK, Lily M, Deka RC, Chandra AK. A theoretical insight into atmospheric chemistry of HFE-7100 and perfluoro-butyl formate: reactions with OH radicals and Cl atoms and the fate of alkoxy radicals. NEW J CHEM 2016. [DOI: 10.1039/c5nj02752g] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The calculated rate constants for C4F9OCH3 + OH/Cl reactions are found to be 1.94 × 10−14 and 1.74 × 10−12 cm3 molecule−1 s−1, respectively, at 298 K. The atmospheric lifetime and global warming potential for HFE-7100 are computed to be 2.12 years and 155.3, respectively.
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Affiliation(s)
| | - Makroni Lily
- Department of Chemistry
- North-Eastern Hill University
- Shillong – 793 022
- India
| | | | - Asit K. Chandra
- Department of Chemistry
- North-Eastern Hill University
- Shillong – 793 022
- India
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30
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Bai FY, Liu YJ, Wang X, Sun YQ, Pan XM. Atmospheric chemistry of CF3(CX2)2CH2OH: rate coefficients and temperature dependence of reactions with chlorine atoms and the subsequent pathways of alkyl and alkoxy radicals (X = H, F). RSC Adv 2016. [DOI: 10.1039/c6ra10840g] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The atmospheric and kinetic properties of CF3(CX2)2CH2OH (X = H, F) with chlorine atoms were studied by density functional and canonical variational transition state theories in conjunction with the small-curvature tunneling correction.
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Affiliation(s)
- Feng-Yang Bai
- Institute of Functional Material Chemistry
- Faculty of Chemistry
- Northeast Normal University
- 130024 Changchun
- People’s Republic of China
| | - You-Jun Liu
- Faculty of Physics
- Aviation University of Air Force
- 130022 Changchun
- People’s Republic of China
| | - Xu Wang
- Institute of Functional Material Chemistry
- Faculty of Chemistry
- Northeast Normal University
- 130024 Changchun
- People’s Republic of China
| | - Yan-Qiu Sun
- Institute of Functional Material Chemistry
- Faculty of Chemistry
- Northeast Normal University
- 130024 Changchun
- People’s Republic of China
| | - Xiu-Mei Pan
- Institute of Functional Material Chemistry
- Faculty of Chemistry
- Northeast Normal University
- 130024 Changchun
- People’s Republic of China
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31
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GOUR NANDKISHOR, MISHRA BHUPESHKUMAR, SINGH HARIJI. Theoretical study on mechanism, kinetics, and thermochemistry of the gas phase reaction of 2,2,2-trifluoroethyl butyrate with OH radicals at 298 K. J CHEM SCI 2015. [DOI: 10.1007/s12039-015-0860-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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32
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Theoretical studies on atmospheric chemistry of (CF3)2C(OH)CH3: Kinetics, mechanism and thermochemistry of gas phase reactions with OH radicals. J Fluor Chem 2015. [DOI: 10.1016/j.jfluchem.2015.04.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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33
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Golubkova O, Shchepkin D, Bertsev V, Sergeev P. Fermi resonances in the vibrational spectrum of perfluoroethane. J Mol Struct 2015. [DOI: 10.1016/j.molstruc.2015.02.059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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34
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Bhattacharjee D, Mishra BK, Deka RC. Theoretical insight on atmospheric chemistry of HFE-365mcf3: reactions with OH radicals, atmospheric lifetime, and fate of alkoxy radicals (CF3CF2CH(O•)OCH3/CF3CF2CH2OCH2O•). J Mol Model 2015; 21:69. [DOI: 10.1007/s00894-015-2629-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2014] [Accepted: 02/15/2015] [Indexed: 11/28/2022]
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35
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Lily M, Chandra AK. Theoretical investigation on kinetics and thermochemistry of reaction of CHF 2CF 2OCH 2CF 3with OH radicals and global warming potentials. Mol Phys 2015. [DOI: 10.1080/00268976.2014.955541] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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36
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Díaz-de-Mera Y, Aranda A, Notario A, Rodríguez A, Rodríguez D, Bravo I. Photolysis study of fluorinated ketones under natural sunlight conditions. Phys Chem Chem Phys 2015; 17:22991-8. [DOI: 10.1039/c5cp03527a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
UV and IR spectra of CF3COCH3 and CF3COC2H5 are provided, with photolysis being their dominant fate in the atmosphere.
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Affiliation(s)
- Yolanda Díaz-de-Mera
- Facultad de Ciencias y Tecnologías Químicas
- Universidad de Castilla La Mancha
- 13071 – Ciudad Real
- Spain
| | - Alfonso Aranda
- Facultad de Ciencias y Tecnologías Químicas
- Universidad de Castilla La Mancha
- 13071 – Ciudad Real
- Spain
| | - Alberto Notario
- Facultad de Ciencias y Tecnologías Químicas
- Universidad de Castilla La Mancha
- 13071 – Ciudad Real
- Spain
| | - Ana Rodríguez
- Facultad de Ciencias Ambientales y Bioquímica
- Universidad de Castilla La Mancha
- 45071 Toledo
- Spain
| | - Diana Rodríguez
- Facultad de Ciencias Ambientales y Bioquímica
- Universidad de Castilla La Mancha
- 45071 Toledo
- Spain
| | - Iván Bravo
- Facultad de Farmacia
- Universidad de Castilla La Mancha
- 02071 Albacete
- Spain
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37
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Infrared Absorption Spectra, Radiative Efficiencies, and Global Warming Potentials of Newly-Detected Halogenated Compounds: CFC-113a, CFC-112 and HCFC-133a. ATMOSPHERE 2014. [DOI: 10.3390/atmos5030473] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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38
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Mechanism and kinetics of the atmospheric degradation of perfluoropolymethylisopropyl ether by OH radical: a theoretical study. Struct Chem 2014. [DOI: 10.1007/s11224-014-0448-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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39
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Mishra BK, Lily M, Chakrabartty AK, Bhattacharjee D, Deka RC, Chandra AK. Theoretical investigation of atmospheric chemistry of volatile anaesthetic sevoflurane: reactions with the OH radicals and atmospheric fate of the alkoxy radical (CF3)2CHOCHFO: thermal decomposition vs. oxidation. NEW J CHEM 2014. [DOI: 10.1039/c3nj01408h] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Reaction profile (kcal mol−1) for (CF3)2CHOCHFO radical at the M06-2X/6-311++G(d,p) level.
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Affiliation(s)
| | - Makroni Lily
- Department of Chemistry
- North-Eastern Hill University
- Shillong, India
| | | | | | | | - Asit K. Chandra
- Department of Chemistry
- North-Eastern Hill University
- Shillong, India
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40
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Papadimitriou VC, McGillen MR, Smith SC, Jubb AM, Portmann RW, Hall BD, Fleming EL, Jackman CH, Burkholder JB. 1,2-Dichlorohexafluoro-cyclobutane (1,2-c-C4F6Cl2, R-316c) a Potent Ozone Depleting Substance and Greenhouse Gas: Atmospheric Loss Processes, Lifetimes, and Ozone Depletion and Global Warming Potentials for the (E) and (Z) Stereoisomers. J Phys Chem A 2013; 117:11049-65. [DOI: 10.1021/jp407823k] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Vassileios C. Papadimitriou
- Earth
System Research Laboratory, Chemical Sciences Division, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, Colorado, 80305 United States
- Cooperative
Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado, 80309 United States
- Laboratory
of Photochemistry and Chemical Kinetics, Department of Chemistry, University of Crete, Vassilika Vouton, 71003 Heraklion, Crete, Greece
| | - Max R. McGillen
- Earth
System Research Laboratory, Chemical Sciences Division, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, Colorado, 80305 United States
- Cooperative
Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado, 80309 United States
| | - Shona C. Smith
- Earth
System Research Laboratory, Chemical Sciences Division, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, Colorado, 80305 United States
- Cooperative
Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado, 80309 United States
| | - Aaron M. Jubb
- Earth
System Research Laboratory, Chemical Sciences Division, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, Colorado, 80305 United States
- Cooperative
Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado, 80309 United States
| | - Robert W. Portmann
- Earth
System Research Laboratory, Chemical Sciences Division, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, Colorado, 80305 United States
| | - Bradley D. Hall
- Earth
System Research Laboratory, Global Monitoring Division, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, Colorado, 80305 United States
| | - Eric L. Fleming
- NASA Goddard Space Flight Center, Greenbelt, Maryland, 20771 United States
- Science Systems and Applications, Inc., Lanham, Maryland, 20706 United States
| | - Charles H. Jackman
- NASA Goddard Space Flight Center, Greenbelt, Maryland, 20771 United States
| | - James B. Burkholder
- Earth
System Research Laboratory, Chemical Sciences Division, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, Colorado, 80305 United States
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Assessment of theoretical methods for the study of hydrogen abstraction kinetics of global warming gas species during their degradation and byproduct formation (IUPAC Technical Report). PURE APPL CHEM 2013. [DOI: 10.1351/pac-rep-10-02-38] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Global climate change is a major concern as it leads to an increase in the
average temperature of the earth’s atmosphere. The existence and
persistence of some gaseous species in the atmosphere contribute to global
warming. Experimental techniques are used to study the kinetics and degradation
of global warming gases. However, quantum mechanical methods are also useful for
the kinetic and radiative forcing study of global warming species and can
precede experimental investigations. Research has also been targeted to develop
more adapted procedures using ab initio and density functional theory (DFT)
methods. This report provides a global perspective, in simplified manner, of the
theoretical studies of the degradation of gas species in the atmosphere with an
emphasis on the hydrogen abstraction kinetics of global warming gas species
during their degradation and byproduct formation. En route, the results obtained
from these studies are analysed and compared with experimental data where
available. Our analyses indicate that the theoretical predictions are in
agreement with experimental findings but the predicted parameters are dependent
on the method being used. Theoretical methods are used to predict the
thermodynamic parameters of reactions, and, with relevance to this report, the
global warming potential (GWP) index can also be calculated. This report can be
useful for future investigations involving global warming gaseous species while
providing suggestions on how computations can fill in data gaps when
experimental data are unavailable.
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Kazakov A, McLinden MO, Frenkel M. Computational Design of New Refrigerant Fluids Based on Environmental, Safety, and Thermodynamic Characteristics. Ind Eng Chem Res 2012. [DOI: 10.1021/ie3016126] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Kokkila SI, Bera PP, Francisco JS, Lee TJ. A group increment scheme for infrared absorption intensities of greenhouse gases. J Mol Struct 2012. [DOI: 10.1016/j.molstruc.2011.11.048] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Wallington T, Hurley M. Atmospheric chemistry of hexafluorocyclobutene, octafluorocyclopentene, and hexafluoro-1,3-butadiene. Chem Phys Lett 2011. [DOI: 10.1016/j.cplett.2011.01.059] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Bravo I, Díaz-de-Mera Y, Aranda A, Moreno E, Nutt DR, Marston G. Radiative efficiencies for fluorinated esters: indirect global warming potentials of hydrofluoroethers. Phys Chem Chem Phys 2011; 13:17185-93. [DOI: 10.1039/c1cp21874c] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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