1
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Yavuz B, Januszewski B, Chen T, Delgado AG, Westerhoff P, Rittmann B. Using radish (Raphanus lativus L.) germination to establish a benchmark dose for the toxicity of ozonated-petroleum byproducts in soil. CHEMOSPHERE 2023; 313:137382. [PMID: 36442677 DOI: 10.1016/j.chemosphere.2022.137382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 10/30/2022] [Accepted: 11/23/2022] [Indexed: 06/16/2023]
Abstract
The concentration-response relationship between the germination outcome of radish (Raphanus lativus L.) and ozonated petroleum residuals was determined experimentally. The outcomes were used to produce an ecological risk assessment model to predict the extra risk of adverse outcomes based on the concentration of ozonated residuals. A test soil with low organic matter (0.5% w/w) was mixed with raw crude oil, artificially weathered, and treated at three doses of ozone (O3) gas (5 g, 10 g, and 40 g O3 per 600 g of soil). Total petroleum hydrocarbons (TPH) and produced dissolved organic carbon (DOC) were measured. TREATMENT categories (control, petroleum, petroleum + 5 g O3, petroleum + 10 g O3, and petroleum + 40 g O3) were then used to create a dilution series using different proportions of the test soil and a commercially available potting mix (∼75% w/w organic matter) to evaluate the effects of background organic matter (b-ORGANIC) in conjunction with TPH and DOC. Multivariable logistic regression was performed on the adverse germination outcome as a function of TPH, DOC, TREATMENT, and b-ORGANIC. The parameters controlling germination were the continuous variable DOC and the categorical variables TREATMENT and b-ORGANIC. Radish germination was strongly harmed by DOC from ozonation, but DOC's ecotoxicity decreased with increasing O3 dose and the presence of b-ORGANIC beyond 10% (w/w). We used the germination outcome of radish to produce a logistic regression model that computes margins of DOC (± std. error) that create 10%, 25%, and 50% extra risk of adverse germination effects.
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Affiliation(s)
- Burcu Yavuz
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, 727 Tyler Road, Tempe, AZ, 85287, USA; School of Sustainable Engineering and the Built Environment, Arizona State University, 660 S College Ave, Tempe, AZ, 85281, USA.
| | - Brielle Januszewski
- Chemical and Environmental Engineering, Yale University, 17 Hillhouse Ave (Room 501), New Haven, CT, 06511, USA
| | - Tengfei Chen
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, 727 Tyler Road, Tempe, AZ, 85287, USA; Geosyntec Consultants, Inc., 11811 N Tatum Blvd, Suite P186, Phoenix, AZ, 85028, USA
| | - Anca G Delgado
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, 727 Tyler Road, Tempe, AZ, 85287, USA; School of Sustainable Engineering and the Built Environment, Arizona State University, 660 S College Ave, Tempe, AZ, 85281, USA; Engineering Research Center for Bio-mediated and Bio-inspired Geotechnics, Arizona State University, 650 E Tyler Mall, Tempe, AZ, 85281, USA
| | - Paul Westerhoff
- School of Sustainable Engineering and the Built Environment, Arizona State University, 660 S College Ave, Tempe, AZ, 85281, USA
| | - Bruce Rittmann
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, 727 Tyler Road, Tempe, AZ, 85287, USA; School of Sustainable Engineering and the Built Environment, Arizona State University, 660 S College Ave, Tempe, AZ, 85281, USA
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Park J, Kim H. Theoretical Study on the Reaction of
p
‐Cymene with Ozone. B KOREAN CHEM SOC 2021. [DOI: 10.1002/bkcs.12294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Jiho Park
- Department of Environmental Health Korea National Open University Seoul 03087 Korea
| | - Hahkjoon Kim
- Department of Chemistry Duksung Women's University Seoul 01369 Korea
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3
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Pfeifle M, Ma YT, Jasper AW, Harding LB, Hase WL, Klippenstein SJ. Nascent energy distribution of the Criegee intermediate CH2OO from direct dynamics calculations of primary ozonide dissociation. J Chem Phys 2018; 148:174306. [DOI: 10.1063/1.5028117] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Mark Pfeifle
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Yong-Tao Ma
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, USA
| | - Ahren W. Jasper
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Lawrence B. Harding
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - William L. Hase
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, USA
| | - Stephen J. Klippenstein
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
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4
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Lv C, Du L, Tang S, Tsona NT, Liu S, Zhao H, Wang W. Matrix isolation study of the early intermediates in the ozonolysis of selected vinyl ethers. RSC Adv 2017. [DOI: 10.1039/c7ra01011g] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The Criegee mechanism of the ozonolysis reaction of vinyl ethers has been observed by matrix isolation FTIR spectroscopy.
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Affiliation(s)
- Chen Lv
- Environment Research Institute
- Shandong University
- China
| | - Lin Du
- Environment Research Institute
- Shandong University
- China
| | - Shanshan Tang
- Environment Research Institute
- Shandong University
- China
| | | | - Shijie Liu
- Environment Research Institute
- Shandong University
- China
| | - Hailiang Zhao
- Environment Research Institute
- Shandong University
- China
| | - Wenxing Wang
- Environment Research Institute
- Shandong University
- China
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5
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Chapleski RC, Morris JR, Troya D. A theoretical study of the ozonolysis of C60: primary ozonide formation, dissociation, and multiple ozone additions. Phys Chem Chem Phys 2015; 16:5977-86. [PMID: 24549406 DOI: 10.1039/c3cp55212h] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
We present an investigation of the reaction of ozone with C60 fullerene using electronic structure methods. Motivated by recent experiments of ozone exposure to a C60 film, we have characterized stationary points in the potential energy surface for the reactions of O3 with C60 that include both the formation of primary ozonide and subsequent dissociation reactions of this intermediate that lead to C-C bond cleavage. We have also investigated the addition of multiple O3 molecules to the C60 cage to explore potential reaction pathways under the high ozone flux conditions used in recent experiments. The lowest-energy product of the reaction of a single ozone molecule with C60 that results in C-C bond breakage corresponds to an open-cage C60O3 structure that contains ester and ketone moieties at the seam. This open-cage product is of much lower energy than the C60O + O2 products identified in prior work, and it is consistent with IR experimental spectra. Subsequent reaction of the open-cage C60O3 product with a second ozone molecule opens a low-energy reaction pathway that results in cage degradation via the loss of a CO2 molecule. Our calculations also reveal that, while full ozonation of all bonds between hexagons in C60 is unlikely even under high ozone concentration, the addition of a few ozone molecules to the C60 cage is favorable at room temperature.
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6
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Priya AM, Senthilkumar L. Reaction of OH radical and ozone with methyl salicylate - a DFT study. J PHYS ORG CHEM 2015. [DOI: 10.1002/poc.3447] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- A. Mano Priya
- Department of Physics; Bharathiar University; Coimbatore 641046 Tamil Nadu India
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7
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Wen Z, Wang Z, Xu J, Liu Y, Cen K. Quantum chemistry study on the destruction mechanism of 2,3,7,8-TCDD by OH and O(3) radicals. CHEMOSPHERE 2013; 92:293-298. [PMID: 23642639 DOI: 10.1016/j.chemosphere.2013.03.027] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Revised: 03/04/2013] [Accepted: 03/16/2013] [Indexed: 06/02/2023]
Abstract
Due to its fundamental importance, the destruction mechanism of the dioxins, as exemplified by 2,3,7,8-TCDD, by OH and O3 radicals was investigated in detail employing Quantum Chemical Calculations in this paper. Theoretical results showed that, OH radical degraded 2,3,7,8-TCDD via substituting chlorine at the 2,3,7,8 positions, while O3 radical degraded 2,3,7,8-TCDD via destructing CC bonds and aromatic ring. Based on the mechanism study, the kinetic parameters of the reactions were also calculated by Transition State Theory. By comparing, the rate constant of the 2,3,7,8-TCDD destruction by OH was found to be much higher than that by O3, which indicated that OH radical have much stronger ability to degrade 2,3,7,8-TCDD than O3 radical. This finding was consistent with the standard electrode potential of OH and O3 radical. The theoretical results in this paper can be believed to supply important theory basis for the further investigation on dioxins removal by using the catalytic oxidation technology.
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Affiliation(s)
- Zhengcheng Wen
- College of Science, Hangzhou Dianzi University, Hangzhou 310018, China.
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8
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Pinelo L, Gudmundsdottir AD, Ault BS. Matrix Isolation Study of the Ozonolysis of 1,3- and 1,4-Cyclohexadiene: Identification of Novel Reaction Pathways. J Phys Chem A 2013; 117:4174-82. [DOI: 10.1021/jp402981n] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Laura Pinelo
- Department of Chemistry, University of Cincinnati, P.O. Box 210172, Cincinnati, Ohio 45221-0172, USA
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9
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Yang J, Miao J, Li X, Xu W. Cycloaddition of ozone to allyl alcohol, acrylic acid and allyl aldehyde: A comparative DFT study. Chem Phys 2013. [DOI: 10.1016/j.chemphys.2013.01.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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10
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Investigation of the mechanism of ozonolysis of (Z)-3-methyl-2-pentene using matrix isolation infrared spectroscopy. J Mol Struct 2013. [DOI: 10.1016/j.molstruc.2012.07.046] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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11
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GOTO Y, FUNASAKA T, YAMAMOTO M, KOIKE K, HORIBE H. Estimation of the Activation Energy of Resist Removal Using Wet Ozone. KOBUNSHI RONBUNSHU 2013. [DOI: 10.1295/koron.70.295] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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12
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Goto Y, Angata Y, Yamamoto M, Seki T, Matsumoto J, Horibe H. Removal of Ion Implanted Poly Vinyl Phenol using Wet Ozone. J PHOTOPOLYM SCI TEC 2013. [DOI: 10.2494/photopolymer.26.467] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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13
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Shin YS, Choi TS, Kim H, Beauchamp JL, Heath JR, Kim HI. A microfluidic-based bubble generation platform enables analysis of physical property change in phospholipid surfactant layers by interfacial ozone reaction. LAB ON A CHIP 2012; 12:5243-8. [PMID: 23117600 PMCID: PMC3681610 DOI: 10.1039/c2lc40940b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The air-liquid interface filled with pulmonary surfactant is a unique feature of our lung alveoli. The mechanical properties of this interface play an important role in breathing and its malfunction induced by an environmental hazard, such as ozone, relates to various lung diseases. In order to understand the interfacial physics of the pulmonary surfactant system, we employed a microfluidic bubble generation platform with a model pulmonary surfactant composed of two major phospholipids: DPPC (1,2-dipalmitoyl-sn-phosphatidylcholine) and POPG (1-palmitoyl-2-oleoyl-sn-phosphatidylglycerol). With fluorescence imaging, we observed the ozone-induced chemical modification of the unsaturated lipid component of the lipid mixture, POPG. This chemical change due to the oxidative stress was further utilized to study the physical characteristics of the interface through the bubble formation process. The physical property change was evaluated through the oscillatory behaviour of the monolayer, as well as the bubble size and formation time. The results presented demonstrate the potential of this platform to study interfacial physics of lung surfactant system under various environmental challenges, both qualitatively and quantitatively.
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Affiliation(s)
- Young Shik Shin
- Nanosystems Biology Cancer Center, California Institute of Technology, MC 127-72, Pasadena, California 91125, USA
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14
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Pinelo L, Ault BS. Infrared matrix isolation and theoretical study of the initial intermediates in the reaction of ozone with cycloheptene. J Mol Struct 2012. [DOI: 10.1016/j.molstruc.2012.05.037] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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15
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Investigation of the thermal and photochemical reactions of ozone with styrene in argon and krypton matrices. J Mol Struct 2012. [DOI: 10.1016/j.molstruc.2012.02.060] [Citation(s) in RCA: 4] [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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16
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Suarez-Bertoa R, Saliu F, Bruschi M, Rindone B. Reaction products and mechanism of the regioselective oxidation of N-phenylmorpholine by ozone. Tetrahedron 2012. [DOI: 10.1016/j.tet.2012.07.055] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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17
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Copeland G, Ghosh MV, Shallcross DE, Percival CJ, Dyke JM. A study of the alkene–ozone reactions, 2,3-dimethyl 2-butene + O3 and 2-methyl propene + O3, with photoelectron spectroscopy: measurement of product branching ratios and atmospheric implications. Phys Chem Chem Phys 2011; 13:17461-73. [DOI: 10.1039/c1cp21922g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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18
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Coleman BE, Ault BS. Investigation of the Thermal and Photochemical Reactions of Ozone with 2,3-Dimethyl-2-butene. J Phys Chem A 2010; 114:12667-74. [DOI: 10.1021/jp108457w] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Bridgett E. Coleman
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221, United States
| | - Bruce S. Ault
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221, United States
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20
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Wang ZH, Wen ZC, Xu JR, Zhou JH, Cen KF. Theoretical Study on Destruction Mechanism of 2,3,7,8-TCDD by O3 and NO3. CHINESE J CHEM PHYS 2010. [DOI: 10.1088/1674-0068/23/03/303-309] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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21
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Clay M, Ault BS. Infrared Matrix Isolation and Theoretical Study of the Initial Intermediates in the Reaction of Ozone with cis-2-Butene. J Phys Chem A 2010; 114:2799-805. [DOI: 10.1021/jp912253t] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Mary Clay
- Department of Chemistryl, University of Cincinnati, P.O. Box 210172, Cincinnati, Ohio 45221-0172
| | - Bruce S. Ault
- Department of Chemistryl, University of Cincinnati, P.O. Box 210172, Cincinnati, Ohio 45221-0172
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22
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Abe Y, Kaneko A, Yagi T, Hamada H, Ike M, Asano T, Kato T, Fujimori K. Effects of UV-irradiation on Removal Process of Photoresist by Aqueous Ozone. KAGAKU KOGAKU RONBUN 2010. [DOI: 10.1252/kakoronbunshu.36.41] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Yutaka Abe
- Graduate School of System and Information Engineering, University of Tsukuba
| | - Akiko Kaneko
- Graduate School of System and Information Engineering, University of Tsukuba
| | - Takahiro Yagi
- Graduate School of System and Information Engineering, University of Tsukuba
| | - Hiroyuki Hamada
- Graduate School of System and Information Engineering, University of Tsukuba
| | | | | | - Takeshi Kato
- Ibaraki Prefectural Industrial Technology Institute
| | - Ken Fujimori
- Tsukuba Industrial Liaison and Cooperative Research Center
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23
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Chen XF, Hou CY, Han KL. DFT Study of Intermolecular [4 + 2] versus [3 + 2] Cycloadditions in the Dimerization of 2,4,6-Trinitrotoluene (TNT): Regioselectivity and Stereoselectivity. J Phys Chem A 2009; 114:1169-77. [DOI: 10.1021/jp909670w] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Xiao-Fang Chen
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, P. R. China
| | - Chun-Yuan Hou
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, P. R. China
| | - Ke-Li Han
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, P. R. China
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24
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Hoops MD, Ault BS. Matrix Isolation Study of the Early Intermediates in the Ozonolysis of Cyclopentene and Cyclopentadiene: Observation of Two Criegee Intermediates. J Am Chem Soc 2009; 131:2853-63. [DOI: 10.1021/ja8065286] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Michael D. Hoops
- Department of Chemistry, University of Cincinnati, P.O. Box 210172, Cincinnati, Ohio 45221-0172
| | - Bruce S. Ault
- Department of Chemistry, University of Cincinnati, P.O. Box 210172, Cincinnati, Ohio 45221-0172
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25
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Jiménez-Osés G, Elguero J, García JI. The unusual reactivity of benzene and monosubstituted benzenes towards tetracyanoethylene oxide: a theoretical study. NEW J CHEM 2009. [DOI: 10.1039/b810220a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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26
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Vayner G, Addepalli SV, Song K, Hase WL. Post-transition state dynamics for propene ozonolysis: Intramolecular and unimolecular dynamics of molozonide. J Chem Phys 2006; 125:014317. [PMID: 16863308 DOI: 10.1063/1.2206785] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
A direct chemical dynamics simulation, at the B3LYP6-31G(d) level of theory, was used to study the post-transition state intramolecular and unimolecular dynamics for the O3 + propene reaction. Comparisons of B3LYP6-31G(d) with CCSD(T)/cc-pVTZ and other levels of theory show that the former gives accurate structures and energies for the reaction's stationary points. The direct dynamics simulations are initiated at the anti and syn O3 + propene transition states (TSs) and the TS symmetries are preserved in forming the molozonide intermediates. Anti<-->syn molozonide isomerization has a very low barrier of 2-3 kcalmol and its Rice-Ramsperger-Kassel-Marcus (RRKM) lifetime is 0.3 ps. However, the trajectory isomerization is slower and it is unclear whether this anti<-->syn equilibration is complete when the trajectories are terminated at 1.6 ps. The syn (anti) molozonides dissociate to CH3CHO + H2COO and H2CO + syn (anti) CH3CHOO. The kinetics for the latter reactions are in overall good agreement with RRKM theory, but there is a symmetry preserving non-RRKM dynamical constraint for the former. Dissociation of anti molozonide to CH3CHO + H2COO is enhanced and suppressed, respectively, for the trajectory ensembles initiated at the anti and syn O3 + propene TSs. The dissociation of syn molozonide to CH3CHO + H2COO may also be enhanced for trajectories initiated at the syn O3 + propene TS. At the time the trajectories are terminated at 1.6 ps, the ratio of the trajectory and RRKM values of the CH3CHO + H2COO product yield is 1.6 if the symmetries of the initiation and dissociation TSs are the same and 0.6 if their symmetries are different. There are coherences in the intramolecular energy flow, which depend on molozonide's symmetry (i.e., anti or syn). This symmetry related dynamics is not completely understood, but it is clearly related to the non-RRKM dynamics for anti<-->syn isomerization and anti molozonide dissociation to CH3CHO + H2COO. Correlations are found between the stretching motions of molozonide, indicative of nonchaotic and non-RRKM dynamics. The non-RRKM dynamics of molozonide dissociation partitions vibration energy to H2COO that is larger than statistical partitioning. Though the direct dynamics simulations are classical, better agreement is obtained using quantum instead of classical harmonic RRKM theory. This may result from the neglect of anharmonicity in the RRKM calculations, the non-RRKM dynamics of the classical trajectories, or a combination of these two effects. The trajectories suggest that the equilibrium syn/anti molozonide ratio is approximately 1.1-1.2 times larger than that predicted by the harmonic densities of state, indicating an anharmonic correction.
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Affiliation(s)
- Grigoriy Vayner
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409-1061, USA
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27
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Imhof W, Anders E. Regioselectivity in Iron-Catalyzed [2+2+1] Cycloadditions: A DFT Investigation of Substituent Effects in 1,4-Diazabutadienes. Chemistry 2004; 10:5717-29. [PMID: 15472944 DOI: 10.1002/chem.200400215] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The transition-metal-catalyzed [2+2+1] cycloaddition reaction of 1,4-diazabutadienes, in which the imine-carbon atoms are part of an oxazine ring system, with ethylene and carbon monoxide leads to the regioselective formation of pyrrolidinone derivatives. To explain this regioselectivity, the transition states and intermediates of the rate-determining step of the catalysis are determined by high-level DFT calculations. The experimentally observed regioselectivity is consistent with the lower activation energy of the addition of ethylene towards the carbon atom next to the oxazine oxygen atom. Furthermore, the activation barrier of a conceivable back reaction is higher for the intermediates with the experimentally observed regioselectivity. These thermodynamic and kinetic arguments at first sight appear to be confirmed by the calculated NPA charges in the transition states, which reveal that the differences in these charges are greatest for those transition states that lead to the formation of the energetically favored transition structures. Nevertheless, calculations of analogous transition structures and reaction products starting from 1,4-diazabutadienes with a 2-fluoro, 2-hydroxo or 2-amino substituent revealed that the regioselectivity is not determined by the electronegativity of the heteroatom and thus by the differences in the NPA charges or the resulting Coulombic interactions in the transition structures. The main reason for the observed regioselectivities is the pi-donor ability of the substituent to contribute to a delocalized pi system incorporating the adjacent imine moiety. The increasing pi-donor capability results in decreased reactivity of this moiety and increases the (relative) reactivity of the second imine group. This effect can even overcompensate for strong intramolecular Coulombic attractions in the transition structures.
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Affiliation(s)
- Wolfgang Imhof
- Institute of Inorganic and Analytical Chemistry of the Friedrich-Schiller-University Jena, August-Bebel-Strasse 2, 07743 Jena, Germany.
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