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Oxidation pathways and kinetics of the 1,1,2,3-tetrafluoropropene (CF 2CF-CH 2F) reaction with Cl-atoms and subsequent aerial degradation of its product radicals in the presence of NO. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2024; 26:734-750. [PMID: 38426396 DOI: 10.1039/d3em00545c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/02/2024]
Abstract
To give a comprehensive account of the environmental acceptability of 1,1,2,3-tetrafluoropropene (CF2CF-CH2F) in the troposphere, we have examined the oxidation reaction pathways and kinetics of CF2CF-CH2F initiated by Cl-atoms using the second-order Møller-Plesset perturbation (MP2) theory along with the 6-31+G(d,p) basis set. We also performed single-point energy calculations to further refine the energies at the CCSD(T) level along with the basis sets 6-31+G(d,p) and 6-311++G(d,p). The estimation of the relative energies and thermodynamic parameters of the CF2CF-CH2F + Cl reaction clearly shows that Cl-atom addition reaction pathways are more dominant compared to H-abstraction reaction pathways. The value of the rate coefficient for each reaction channel is calculated using the conventional transition state theory (TST) over the temperature range of 200-1000 K at 1 atm. The estimated overall rate coefficients for the title reaction are found to be 1.10 × 10-12, 1.21 × 10-10, and 1.13 × 10-8 cm3 per molecule per s via the respective calculation methods viz. MP2/6-31+G(d,p), CCSD(T)//MP2/6-31+G(d,p), and CCSD(T)/6-311++G(d,p)//MP2/6-31+G(d,p), at 298.15 K. Moreover, the calculated rate coefficients and percentage branching ratio values suggest that the Cl-atom addition reaction at the β-carbon atom is more preferable to that of the α-carbon addition to CF2CF-CH2F. Based on the rate coefficient values calculated by the three different methods, the atmospheric lifetime for the title reaction at 298.15 K is estimated. The radiative efficiency (RE) and Global Warming Potential (GWP) results of the title molecule show that its GWP would be negligible. Further, we have explored the degradation of its product radicals in the presence of O2 and NO. From the degradation results, we have found that CF2(Cl)COF, FCOCH2F, FCFO and FCOCl are formed as stable end products along with various radicals such as ˙CF2Cl and ˙CH2F. Therefore, these findings of kinetic and mechanistic data can be applied to the development and implementation of a novel CFC replacement.
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Unprecedented iron-assisted room temperature synthesis of AgCN using acetonitrile. RSC Adv 2024; 14:10416-10421. [PMID: 38567347 PMCID: PMC10985703 DOI: 10.1039/d4ra01790k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Accepted: 03/25/2024] [Indexed: 04/04/2024] Open
Abstract
A straightforward and convenient approach for producing AgCN at room temperature using acetonitrile as a source has been developed, employing various iron salts. To date, there have been no prior studies documenting the synthesis of AgCN by cleaving the C-CN bond in acetonitrile with the use of iron salts. The resulting highly crystalline material was subjected to characterization through XRD and FT-IR analysis. Additionally, the same process was used for C-CN bond breaking using Ag2S or via the formation of an AgSxOy composite. Consequently, this report is primarily dedicated to exploring the efficacy of different iron salts in breaking the C-CN bond in CH3CN. A theoretical investigation of the proposed experimental scheme has also been performed to confer the feasibility of the reaction.
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Reaction Mechanism and Kinetics for the Selective Hydrogenation of Carbon Dioxide to Formic Acid and Methanol over the [Cu 2] 0,±1 Dimer. J Phys Chem A 2023; 127:8508-8529. [PMID: 37811794 DOI: 10.1021/acs.jpca.3c03609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
With the rapid growth of industrialization, deforestation, and burning of fossil fuels, undeniably there has been an incredible escalation of the CO2 concentration in the atmosphere. In order to mitigate the problem, the capture and utilization of CO2 in different value-added chemicals have thus remained topics of concerned research for more than a decade. Accordingly, we have performed molecular -level catalytic hydrogenation of CO2 to formic acid using bare [Cu2]0,±1 dimers as catalysts. The entire investigation has been performed using a density functional theory (DFT) method employing the Perdew-Burke-Ernzerhof (PBE) functional with the def2TZVPP basis set to explore the different possible routes and efficiency of the catalysts. Results reveal the feasibility of H2 dissociation on all three Cu2, Cu2+, and Cu2- dimers. The negatively charged hydride formed during H2 dissociation on Cu2 and Cu2+ dimers facilitates the formation of the HCOO* intermediate over COOH*, thereby providing product selectivity for HCOOH above CO. However, the reaction on the Cu2- dimer forms both HCOO* and COOH* intermediates, but HCOO*, being kinetically more favorable, results in HCOOH production. The free-energy change suggests that the complete reaction on Cu2 and Cu2+ dimers forms a stable product compared to the Cu2- dimer. Furthermore, H3COH production is studied using the title catalysts via the obtained HCOOH* intermediate from the reaction channel. Transition state theory (TST) has been considered to evaluate the rate constants for each step of the reaction. Overall results suggest Cu2 to be better compared to Cu2+ and Cu2- dimers for HCOOH formation and Cu2+ over Cu2 and Cu2- dimers to be more efficient for H3COH formation. This work opens the way for further investigation of the reaction mechanism and development of an efficient catalyst for CO2 hydrogenation.
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The molecular level study of the fate of the CH 3CH 2C(O)OCH(O)CH 3 radical derived from ethyl propionate. MOLECULAR SIMULATION 2023. [DOI: 10.1080/08927022.2023.2189975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/31/2023]
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Visible Light‐Induced Synthesis of 2‐Oxazolidinones through One‐Pot Coupling of Benzylamines, Epoxides and CO2. European J Org Chem 2023. [DOI: 10.1002/ejoc.202201338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
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6
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Atmospheric degradation, mechanism and kinetics of ethyl vinyl ketone (CH 2=CHCOCH 2CH 3) initiated by Cl atom: an insight from DFT study. Mol Phys 2022. [DOI: 10.1080/00268976.2022.2100835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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7
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Light-induced synthesis of unsymmetrical organic carbonates from alcohols, methanol and CO 2 under ambient conditions. Chem Commun (Camb) 2021; 57:12800-12803. [PMID: 34783333 DOI: 10.1039/d1cc05833a] [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
The present work describes the first visible light-assisted, metal-free and organic base 1,1,3,3-tetramethyl guanidine (TMG) mediated synthesis of unsymmetrical methyl aryl/alkyl carbonates from the reaction of alcohols, methanol, and CO2 in high to excellent yields under atmospheric pressure and ambient temperature conditions.
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8
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Catalytic oxidation of NO to NO2 on pure and doped AunPt3-n (n=0–3) clusters: A DFT perspective. MOLECULAR CATALYSIS 2021. [DOI: 10.1016/j.mcat.2021.111910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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9
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Atmospheric insight into the reaction mechanism and kinetics of isopropenyl methyl ether (i-PME) initiated by OH radicals and subsequent oxidation of product radicals. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:45646-45662. [PMID: 33876365 DOI: 10.1007/s11356-021-13928-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 04/09/2021] [Indexed: 06/12/2023]
Abstract
Studies on primary gas-phase reactions of emitted saturated and unsaturated ethers with oxidants and subsequent secondary reactions of product radicals with O2 in the presence of NO are important in their atmospheric chemical processes. To accomplish these findings, we have examined the chemistry of OH-initiated oxidation of isopropenyl methyl ether (i-PME) CH3C(CH2)OCH3 by electronic structure ca using density functional theory. Our energetic calculations show that OH additions to carbon-carbon double bonds of i-PME are more favorable reaction pathways than H-abstraction reactions from the various CH sites of the titled molecule. The rate constant values which are obtained from the transition state theory also signify that OH-addition reactions have faster reaction rates than H-abstraction reactions. Our calculated total rate constant of the reaction is found 9.90 × 10-11 cm3 molecule-1 s-1. The percentage branching ratio calculations imply that OH-addition reactions have 98.09% contribution in the total rate constant. The atmospheric lifetime of i-PME is found to be 2.8 h. Further, we have identified 2-hydroxy-2-methoxypropanol, methyl acetate, methy-1,2-hydroxyacetate and 1-hydroxypropane-2-one, 1,2-dihydroxypropan-2-yl format, 2-hydroxyacetic acid, acetic acid, and formaldehyde from the secondary oxidation of product radicals.
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Mechanism and kinetics of catalytic oxidation of CO to CO2 over Ptn+and MPtn-1+, (M=Sn, Rh &Ru; n=3, 4) clusters. MOLECULAR CATALYSIS 2021. [DOI: 10.1016/j.mcat.2021.111638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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11
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Computational modelling of nanotube delivery of anti-cancer drug into glutathione reductase enzyme. Sci Rep 2021; 11:4950. [PMID: 33654109 PMCID: PMC7925602 DOI: 10.1038/s41598-021-84006-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 06/25/2020] [Indexed: 11/20/2022] Open
Abstract
Density functional theory method combined with docking and molecular dynamics simulations are used to understand the interaction of carmustine with human glutathione reductase enzyme. The active site of the enzyme is evaluated by docking simulation is used for molecular dynamics simulation to deliver the carmustine molecule by (5,5) single walled carbon nanotube (SWCNT). Our model of carmustine in the active site of GR gives a negative binding energy that is further refined by QM/MM study in gas phase and solvent phase to confirm the stability of the drug molecule inside the active site. Once released from SWCNT, carmustine forms multiple polar and non-polar hydrogen bonding interactions with Tyr180, Phe209, Lys318, Ala319, Leu320, Leu321, Ile350, Thr352 and Val354 in the range of 2–4 Å. The SWCNT vehicle itself is held fix at its place due to multiple pi-pi stacking, pi-amide, pi-sigma interactions with the neighboring residues. These interactions in the range of 3–5 Å are crucial in holding the nanotube outside the drug binding region, hence, making an effective delivery. This study can be extended to envisage the potential applications of computational studies in the modification of known drugs to find newer targets and designing new and improved controlled drug delivery systems.
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Ring-opening pathway of 2, 4, 6-trichlorophenol initiated by OH radical: an insight from first principle study. Mol Phys 2020. [DOI: 10.1080/00268976.2020.1779364] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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13
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Atmospheric oxidation of 2-fluoropropene (CH3CFCH2) with Cl atom and aerial degradation of its product radicals by computational study. NEW J CHEM 2020. [DOI: 10.1039/c9nj05437e] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Primary degradation of 2-fluoropropene initiated by Cl atom and subsequent degradation of its product radials.
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Tropospheric degradation of 2-fluoropropene (CH 3CFCH 2) initiated by hydroxyl radical: Reaction mechanisms, kinetics and atmospheric implications from DFT study. CHEMOSPHERE 2020; 238:124556. [PMID: 31422310 DOI: 10.1016/j.chemosphere.2019.124556] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 08/02/2019] [Accepted: 08/09/2019] [Indexed: 06/10/2023]
Abstract
Degradation of hydrofluoro-olefins (HFOs) with oxidants plays a significant role in the troposphere. Thus, we have investigated detail theoretical calculations of hydroxyl radical (•OH) initiated oxidation of 2-fluoropropene (CH3CFCH2) using M06-2X/6-311++G(d,p) level of theory. Here, we have considered different possible H-abstraction and OH addition for the degradation of CH3CFCH2 molecule. The potential energy analysis shows that OH-addition channels are more dominant than H-abstraction channels. The calculated reaction enthalpies (ΔrH°) and Gibbs free energies (ΔrG°) also suggest that OH-addition reaction channels are more favourable than H-abstraction channels. The overall rate coefficients for CH3CFCH2 + •OH reaction is calculated within the temperature range of 250-450 K. The observed overall rate coefficient (2.01 × 10-11 cm3 molecule-1 s-1) at 298 K for the titled reaction is found to be in good agreement with the earlier reported experimental rate coefficient. The calculated percentage branching ratio shows that the contribution of OH-addition to α-carbon and β-carbon of CH3CFCH2 molecule are 85.10% and 14.20% to the overall rate coefficient while H-abstractions have a negligible contribution. Based on the kinetics calculations, the atmospheric lifetime of the titled molecule is found to be 0.6 days. Further, we have also explored the degradation pathways of OH-addition product radicals and found acetyl fluoride (CH3CFO) and formaldehyde (HCHO) are the end degradation products.
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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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Oxidation pathways, kinetics and branching ratios of chloromethyl ethyl ether (CMEE) initiated by OH radicals and the fate of its product radical: an insight from a computational study. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2019; 21:1519-1531. [PMID: 31274139 DOI: 10.1039/c9em00104b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The OH-initiated oxidation reactions of chloromethyl ethyl ether (CH2ClOCH2CH3) have been presented by using quantum calculation methods. The Minnesota functional (M06-2X) of the density functional theory method along with a polarization and diffuse 6-311++G(d,p) basis set is chosen for optimization and frequency calculations for H-abstractions from CH2ClOCH2CH3 molecules by OH radicals. Furthermore, the CCSD(T) method along with the same basis set is used for energy refinement of all optimized structures to obtain more accurate energies of the species. Our thermo-chemical calculation results show that the C˙HClOCH2CH3 product radical is more stable, corresponding to hydrogen atom abstraction from the -CH2Cl site, than others while the energy profile results indicate that the H-atom abstracted from the -OCH2 site follows the minimum energy path compared to other channels. The rate constants are computed using canonical transition state theory (CTST) within the temperature range of 250-450 K at 1 atm. The overall rate constant (at 298 K) for the abstraction reactions is found to be consistent with the earlier reported rate constant. The percentage branching ratios of different abstraction channels and the lifetime of chloromethyl ethyl ether are also given herein. We further investigated the unimolecular decomposition pathways of the CH2ClOCH(O˙)CH3 radical and found that unimolecular C-C bond scission is the kinetically and thermodynamically more feasible pathway compared to other unimolecular decomposition reactions.
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Effect of single metal dopant (Rh, Ru and Sn) on Pt+ (n = 3 and 4) clusters for controlled CO tolerance. Chem Phys Lett 2019. [DOI: 10.1016/j.cplett.2019.01.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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18
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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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Kinetics and mechanism of 3-chloro-2-methyl-1-propene(3-ClMP) initiated by OH radical: an insight from DFT calculations [1]. Mol Phys 2019. [DOI: 10.1080/00268976.2018.1509146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Mechanistic investigation of the atmospheric oxidation of bis(2-chloroethyl) ether (ClCH2CH2OCH2CH2Cl) by OH and NO3 radicals and Cl atoms: a DFT approach. J Mol Model 2019; 25:43. [DOI: 10.1007/s00894-019-3923-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 01/03/2019] [Indexed: 10/27/2022]
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Quantum mechanical study on the oxidation of ethyl vinyl ketone initiated by an OH radical. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2018; 20:1708-1715. [PMID: 30339175 DOI: 10.1039/c8em00365c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Oxidation of ethyl vinyl ketone (CH2CHCOCH2CH3) by an OH radical was carried out using the M06-2X/6-311++G(d,p) level of theory. For the OH-initiated oxidation of ethyl vinyl ketone (EVK), we have considered six H-atom abstractions and three addition reactions. From the energetic calculation of the species involved therein, the potential energy surface (PES) of all the reaction channels was constructed. From the energy profile, we found that the H-atom abstraction from the methylene group (-CH2-) of CH2CHCOCH2CH3 is energetically more favourable than the other H-abstraction channels. Moreover, we also observed that OH-addition to the α-carbon of the carbon-carbon double bond of the title molecule is energetically and thermodynamically more dominant than β-carbon and carbonyl carbon. The rate coefficients for all the reaction channels were calculated using the canonical transition state theory at the temperature range of 250-450 K and it reveals that among all the reaction channels, OH-addition to α-carbon is kinetically more dominant to the total rate constant. The total rate coefficient for the reaction at 298 K is found to be in good agreement with the reported experimental rate constant. Finally, we have determined the atmospheric lifetime of the title molecule.
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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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Understanding the Atmospheric Oxidation of HFE-7500 (C3F7CF(OC2H5)CF(CF3)2) Initiated by Cl Atom and NO3 Radical from Theory. J Phys Chem A 2018; 122:6799-6808. [DOI: 10.1021/acs.jpca.8b04225] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Theoretical prediction of the mechanistic pathways and kinetics of methylcyclohexane initiated by OH radicals. Mol Phys 2018. [DOI: 10.1080/00268976.2018.1436202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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25
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Quantum chemical study on the reaction mechanism and kinetics of Cl-initiated oxidation of methyl n-propyl ether. Theor Chem Acc 2018. [DOI: 10.1007/s00214-018-2239-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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OH-initiated mechanistic pathways and kinetics of camphene and fate of product radical: a DFT approach. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:2147-2156. [PMID: 29116529 DOI: 10.1007/s11356-017-0646-2] [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: 09/12/2017] [Accepted: 10/30/2017] [Indexed: 06/07/2023]
Abstract
Present manuscript represents the DFT studies on the oxidation reaction of camphene initiated by OH radical and fate of product radicals using M06-2X functional along with 6-31+G(d,p) basis set. Intrinsic reaction calculation is done for transition states involving OH-addition reactions which proceed via reaction complexes proceeding to the formation of transition states. The rate constant calculated by using canonical transition state theory at 298 K and 1 atm is found to be 5.67 × 10-11 cm3 molecule-1 s-1 which is in good agreement with the experimental rate constant. The atmospheric lifetime of the titled molecule has also been reported in our work.
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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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Atmospheric chemistry of HFE-7000 (i-C3F7OCH3) and isofluoro-propyl formate (i-C3F7OC(O)H): reactions with OH radicals, atmospheric lifetime and fate of alkoxy radical (i-C3F7OCH2O•) – a DFT study. Mol Phys 2015. [DOI: 10.1080/00268976.2015.1108471] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Theoretical investigation on the kinetics and branching ratio of the gas phase reaction of sevoflurane with Cl atom. J Mol Model 2013; 19:4815-22. [DOI: 10.1007/s00894-013-1977-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2013] [Accepted: 08/21/2013] [Indexed: 10/26/2022]
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