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Deb B, Mahanta H, Baruah NP, Khardewsaw M, Paul AK. On the intramolecular vibrational energy redistribution dynamics of aromatic complexes: A comparative study on C6H6-C6H5Cl, C6H6-C6H3Cl3, C6H6-C6Cl6 and C6H6-C6H5F, C6H6-C6H3F3, C6H6-C6F6. J Chem Phys 2024; 160:024307. [PMID: 38197444 DOI: 10.1063/5.0174748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2023] [Accepted: 12/17/2023] [Indexed: 01/11/2024] Open
Abstract
Chemical dynamics Simulation studies on benzene dimer (Bz2) and benzene-hexachlorobenzene (Bz-HCB) as performed in the past suggest that the coupling between the monomeric (intramolecular) vibrational modes and modes generated due to the association of two monomers (intermolecular) has to be neither strong nor weak for a fast dissociation of the complex. To find the optimum coupling, four complexes are taken into consideration in this work, namely, benzene-monofluorobenzene, benzene-monochlorobenzene, benzene-trifluorobenzene (Bz-TFB), and benzene-trichlorobenzene. Bz-TFB has the highest rate of dissociation among all seven complexes, including Bz2, Bz-HCB, and Bz-HFB (HFB stands for hexafluorobenzene). The set of vibrational frequencies of Bz-TFB is mainly the reason for this fast dissociation. The mass of chlorine in Bz-HCB is optimized to match its vibrational frequencies similar to those of Bz-TFB, and the dissociation of Bz-HCB becomes faster. The power spectrum of Bz-TFB, Bz-HCB, and Bz-HCB with the modified mass of chlorine is also computed to understand the extent of the said coupling in these complexes.
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Affiliation(s)
- Basudha Deb
- Department of Chemistry, National Institute of Technology Meghalaya Bijni Complex, Laitumkhrah, Shillong 793003, India
| | - Himashree Mahanta
- Department of Chemistry, National Institute of Technology Meghalaya Bijni Complex, Laitumkhrah, Shillong 793003, India
- Department of Chemistry, Assam Kaziranga University, Koraikhowa, NH-37, Jorhat 785006, India
| | - Netra Prava Baruah
- Department of Chemistry, National Institute of Technology Meghalaya Bijni Complex, Laitumkhrah, Shillong 793003, India
| | - Maitjingshai Khardewsaw
- Department of Chemistry, National Institute of Technology Meghalaya Bijni Complex, Laitumkhrah, Shillong 793003, India
| | - Amit Kumar Paul
- Department of Chemistry, National Institute of Technology Meghalaya Bijni Complex, Laitumkhrah, Shillong 793003, India
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Zhao H, Wang S, Sun J, Zhang Y, Tang Y. OH-initiated degradation of 1,2,3-trimethylbenzene in the atmosphere and wastewater: Mechanisms, kinetics, and ecotoxicity. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 857:159534. [PMID: 36272473 DOI: 10.1016/j.scitotenv.2022.159534] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 10/13/2022] [Accepted: 10/13/2022] [Indexed: 06/16/2023]
Abstract
1,2,3-Trimethylbenzene (1,2,3-TMB) is an important volatile organic compound (VOC) present in petroleum wastewater and the atmosphere. This compound can be degraded by OH radicals via abstraction, addition and substitution mechanisms. Results show that the addition mechanism is dominant and H-abstraction is subdominant, while methyl abstraction and substitution mechanisms are negligible in the gas and aqueous phases. Moreover, H-abstraction products undergo further reactions with O2, NO, NO2, H2O, and OH radicals in the atmosphere. Time-dependent density functional theory (TDDFT) calculations show that the degraded products, including 2,3,4-trimethylphenyl-nitroperoxoite, 1,2,3-trimethyl-4-nitrobenzene, 1,2,3-trimethyl-5-nitrobenzene, 2,6-dimethylbenzyl nitroperoxoite, 2,3-dimethylphenyl nitroperoxoite, 2,6-dimethylbenzaldehyde, and 2,3-dimethylbenzaldehyde, can photolyze under the sunlight. Kinetically, the calculated total rate constant is 5.57 × 10-11 cm3 molecule-1·s-1 at 1 atm and 298 K, which is consistent with available experimental values measured in the atmosphere. In addition, the calculated total reaction rate constant in water is close to that in the gas phase. In terms of ecotoxicity, all degradation products are less toxic than the initial reactant to fish, green algae and daphnia. For mammals represented by rats, 1,2,3-TMB and its products are moderately toxic, except for 2,3-dimethylphenol and 2,6-dimethylphenol, which are slightly toxic.
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Affiliation(s)
- Hui Zhao
- School of Environmental and Municipal Engineering, Qingdao University of Technology, Fushun Road 11, Qingdao, Shandong 266033, PR China
| | - Shuangjun Wang
- School of Environmental and Municipal Engineering, Qingdao University of Technology, Fushun Road 11, Qingdao, Shandong 266033, PR China
| | - Jingyu Sun
- College of Chemistry and Environmental Engineering, Hubei Normal University, Cihu Road 11, Huangshi, Hubei 435002, PR China
| | - Yunju Zhang
- College of Chemistry and Chemical Engineering, Mianyang Normal University, Mianyang 621000, PR China
| | - Yizhen Tang
- School of Environmental and Municipal Engineering, Qingdao University of Technology, Fushun Road 11, Qingdao, Shandong 266033, PR China.
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Zhao H, Wang S, Sun J, Lu C, Tang Y. A new theoretical investigation on ·OH initiated oxidation of acephate in the environment: mechanism, kinetics, and toxicity. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2022; 24:1912-1922. [PMID: 36156666 DOI: 10.1039/d2em00254j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Acephate (O,S-dimethyl acetylphosphoramidothioate) is a typical organophosphorus pesticide used widely in agriculture. It can be released into the atmosphere and water during production and application. In this work, mechanisms in the ·OH initiated degradation of acephate were investigated using quantum chemical methods. Results show that addition, substitution and H-abstraction mechanisms can take place, with the latter being dominant. Moreover, the subsequent reactions of dominant products with O2 and NO in the atmosphere were considered, as well. The rate constant in the atmosphere and aqueous phase was calculated by transition state theory (TST) with the Wigner tunneling contribution. The total rate constant in the atmosphere and aqueous phase is 7.86 × 10-10 and 1.83 × 10-12 cm3 per molecule per s, respectively, the latter being in accordance with the available experimental value of 1.50 × 10-12 cm3 per molecule per s. Moreover, the ecotoxicity of acephate and degradation products was assessed in fish, daphnia, green algae and rats.
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Affiliation(s)
- Hui Zhao
- School of Environmental and Municipal Engineering, Qingdao University of Technology, Fushun Road 11, Qingdao, Shandong, 266033, PR China.
| | - Shuangjun Wang
- School of Environmental and Municipal Engineering, Qingdao University of Technology, Fushun Road 11, Qingdao, Shandong, 266033, PR China.
| | - Jingyu Sun
- College of Chemistry and Environmental Engineering, Hubei Normal University, Cihu Road 11, Huangshi, Hubei, 435002, PR China
| | - Chenggang Lu
- School of Environmental and Municipal Engineering, Qingdao University of Technology, Fushun Road 11, Qingdao, Shandong, 266033, PR China.
| | - Yizhen Tang
- School of Environmental and Municipal Engineering, Qingdao University of Technology, Fushun Road 11, Qingdao, Shandong, 266033, PR China.
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Nguyen HT, Mai TVT, Huynh LK. Detailed kinetic mechanism for CH 3 OO + NO reaction – An ab initio study. COMPUT THEOR CHEM 2017. [DOI: 10.1016/j.comptc.2017.04.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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5
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Burke MP. Harnessing the Combined Power of Theoretical and Experimental Data through Multiscale Informatics. INT J CHEM KINET 2016. [DOI: 10.1002/kin.20984] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Michael P. Burke
- Department of Mechanical Engineering; Department of Chemical Engineering, and Data Science Institute; Columbia University; New York NY 10027
- Chemical Sciences and Engineering Division; Argonne National Laboratory; Argonne IL 60439
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Launder AM, Agarwal J, Schaefer HF. Exploring mechanisms of a tropospheric archetype: CH3O2 + NO. J Chem Phys 2015; 143:234302. [PMID: 26696057 DOI: 10.1063/1.4937381] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Methylperoxy radical (CH3O2) and nitric oxide (NO) contribute to the propagation of photochemical smog in the troposphere via the production of methoxy radical (CH3O) and nitrogen dioxide (NO2). This reaction system also furnishes trace quantities of methyl nitrate (CH3ONO2), a sink for reactive NOx species. Here, the CH3O2 + NO reaction is examined with highly reliable coupled-cluster methods. Specifically, equilibrium geometries for the reactants, products, intermediates, and transition states of the ground-state potential energy surface are characterized. Relative reaction enthalpies at 0 K (ΔH0K) are reported; these values are comprised of electronic energies extrapolated to the complete basis set limit of CCSDT(Q) and zero-point vibrational energies computed at CCSD(T)/cc-pVTZ. A two-part mechanism involving CH3O and NO2 production followed by radical recombination to CH3ONO2 is determined to be the primary channel for formation of CH3ONO2 under tropospheric conditions. Constrained optimizations of the reaction paths at CCSD(T)/cc-pVTZ suggest that the homolytic bond dissociations involved in this reaction path are barrierless.
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Affiliation(s)
- Andrew M Launder
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, USA
| | - Jay Agarwal
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, USA
| | - Henry F Schaefer
- Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, USA
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7
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Pritchard HO. Validating potential energy surfaces for classical trajectory calculations. RSC Adv 2015. [DOI: 10.1039/c5ra06732d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Potential energy distributions for normal and reacting molecules.
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Butkovskaya NI, Kukui A, Le Bras G, Rayez MT, Rayez JC. Pressure dependence of butyl nitrate formation in the reaction of butylperoxy radicals with nitrogen oxide. J Phys Chem A 2014; 119:4408-17. [PMID: 25380343 DOI: 10.1021/jp509427x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The yield of 1- and 2-butyl nitrates in the gas-phase reactions of NO with n-C4H9O2 and sec-C4H9O2, obtained from the reaction of F atoms with n-butane in the presence of O2, was determined over the pressure range of 100-600 Torr at 298 K using a high-pressure turbulent flow reactor coupled with a chemical ionization quadrupole mass spectrometer. The yield of butyl nitrates was found to increase linearly with pressure from about 3% at 100 Torr to about 8% at 600 Torr. The results obtained are compared with the available data concerning nitrate formation from NO reaction with other small alkylperoxy radicals. These results are also discussed through the topology of the lowest potential energy surface mainly obtained from DFT(B3LYP/aug-cc-pVDZ) calculations of the RO2 + NO reaction paths. The formation of alkyl nitrates, due essentially to collision processes, is analyzed through a model that points out the pertinent physical parameters of this system.
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Affiliation(s)
- N I Butkovskaya
- †Institut de Combustion, Aérothermique, Réactivité et Environnement (ICARE), CNRS-INSIS, 1C Avenue de la Recherche Scientifique, 45071 Orléans cedex 2, France
| | - A Kukui
- ‡Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), CNRS-INSU, 3A Avenue de la Recherche Scientifique, 45071 Orléans cedex 2, France
| | - G Le Bras
- †Institut de Combustion, Aérothermique, Réactivité et Environnement (ICARE), CNRS-INSIS, 1C Avenue de la Recherche Scientifique, 45071 Orléans cedex 2, France
| | - M-T Rayez
- §Institut des Sciences Moléculaires, CNRS/UMR5255, Université Bordeaux 1, 351 Cours de la Libération, 33405 Talence cedex, France
| | - J-C Rayez
- §Institut des Sciences Moléculaires, CNRS/UMR5255, Université Bordeaux 1, 351 Cours de la Libération, 33405 Talence cedex, France
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Xiang T, Si H. A computational investigation of product channels in the CH3O2+F reaction. COMPUT THEOR CHEM 2014. [DOI: 10.1016/j.comptc.2013.11.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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10
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Lesar A. Mechanistic study on the reaction of the CH2ClO2 radical with NO. Chem Phys Lett 2013. [DOI: 10.1016/j.cplett.2013.06.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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11
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Pritchard HO. Defective modelling of chaotic motions on empirical potential energy surfaces. RSC Adv 2013. [DOI: 10.1039/c3ra43937b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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12
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Vereecken L, Francisco JS. Theoretical studies of atmospheric reaction mechanisms in the troposphere. Chem Soc Rev 2012; 41:6259-93. [DOI: 10.1039/c2cs35070j] [Citation(s) in RCA: 311] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Abstract
AbstractThe numerical simulation of the internal motions of a molecule undergoing a unimolecular reaction on an assumed potential energy surface requires the step-by-step solution of a set of simultaneous differential equations. After several thousand time steps, due to differences in the handling of rounding errors in different computing systems, the situation often arises that no two computing machines will give the same result for a given trajectory, even when running the identical algorithm. Such effects are demonstrated for a simple unimolecular isomerisation reaction. In general, it is only when reliance is placed on the integration of a single trajectory, rather than on an ensemble of similar trajectories, that conclusions may be unreliable. Moreover, under certain conditions, small molecules may show signs of chaotic internal motions; conversely, but for a different reason, large molecules may exhibit non-statistical characteristics rather than RRKM behaviour. The rounding error problem, in a slightly different guise, has come to be dubbed the “butterfly effect” in popular culture, and the original proposition is re-examined using 16- and 32-decimal precision arithmetic.
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15
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Koseki J, Kita Y, Nagashima U, Tachikawa M. Theoretical study of the reversible photoconversion mechanism in Dronpa. ACTA ACUST UNITED AC 2011. [DOI: 10.1016/j.procs.2011.04.027] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Kuwata KT, Hermes MR, Carlson MJ, Zogg CK. Computational studies of the isomerization and hydration reactions of acetaldehyde oxide and methyl vinyl carbonyl oxide. J Phys Chem A 2010; 114:9192-204. [PMID: 20701322 DOI: 10.1021/jp105358v] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Alkene ozonolysis is a major source of hydroxyl radical (*OH), the most important oxidant in the troposphere. Previous experimental and computational work suggests that for many alkenes the measured *OH yields should be attributed to the combined impact of both chemically activated and thermalized syn-alkyl Criegee intermediates (CIs), even though the thermalized CI should be susceptible to trapping by molecules such as water. We have used RRKM/master equation and variational transition state theory calculations to quantify the competition between unimolecular isomerization and bimolecular hydration reactions for the syn and anti acetaldehyde oxide formed in trans-2-butene ozonolysis and for the CIs formed in isoprene ozonolysis possessing syn-methyl groups. Statistical rate theory calculations were based on quantum chemical data provided by the B3LYP, QCISD, and multicoefficient G3 methods, and thermal rate constants were corrected for tunneling effects using the Eckart method. At tropospheric temperatures and pressures, all thermalized CIs with syn-methyl groups are predicted to undergo 1,4-hydrogen shifts from 2 to 8 orders of magnitude faster than they react with water monomer at its saturation number density. For thermalized anti acetaldehyde oxide, the rates of dioxirane formation and hydration should be comparable.
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Affiliation(s)
- Keith T Kuwata
- Department of Chemistry, Macalester College, Saint Paul, Minnesota 55105-1899, USA.
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Barker JR, Weston RE. Collisional Energy Transfer Probability Densities P(E, J; E′, J′) for Monatomics Colliding with Large Molecules. J Phys Chem A 2010; 114:10619-33. [DOI: 10.1021/jp106443d] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- John R. Barker
- Atmospheric, Oceanic, and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109-2143, and Department of Chemistry, Brookhaven National Laboratory, Upton, New York 11973
| | - Ralph E. Weston
- Atmospheric, Oceanic, and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109-2143, and Department of Chemistry, Brookhaven National Laboratory, Upton, New York 11973
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Kosmas AM, Salta Z, Lesar A. Effect of halogenation on the mechanism of the atmospheric reactions between methylperoxy radicals and NO. A computational study. J Phys Chem A 2009; 113:3545-54. [PMID: 19301893 DOI: 10.1021/jp808895a] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The mechanism of the reactions between the halogenated methylperoxy radicals, CHX(2)O(2) (X = F, Cl), and NO is investigated by using ab initio and density functional quantum mechanical methods. Comparison is made with the mechanism of the CH(3)O(2) + NO reaction. The most important energy minima in the potential energy surface are found to be the two conformers of the halogenated methyl peroxynitrite association adducts, CHX(2)OONOcp and CHX(2)OONOtp, and the halogenated methyl nitrates, CHX(2)ONO(2). The latter are suggested to be formed through the one-step isomerization of the peroxynitrite adduct and may lead upon decomposition to carbonylated species, CX(2)O + HONO and CHXO + XNO(2). The ambiguous issue of the unimolecular peroxynitrite to nitrate isomerization is reconsidered, and the possibility of a triplet transition state involvement in the ROONOtp <--> RONO(2) rearrangement is examined. The overall calculations and the detailed correlation with the methyl system show the significant effect of the halogenation on the lowering of the entrance potential energy well which corresponds to the formation of the peroxynitrites. The increased attractive character of the potential energy surface found upon halogenation combined with the increased exothermicity of the CHX(2)O(2) + NO --> CHX(2)O + NO(2) reaction are suggested to be the important factors contributing to the enhanced reactivity of the halogenated reactions relative to CH(3)O(2) + NO. The calculated heat of formation values indicate the large stabilization of the fluorinated derivatives.
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Affiliation(s)
- Agnie M Kosmas
- Division of Physical Chemistry, Department of Chemistry, University of Ioannina, Greece 45110
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Glowacki DR, Reed SK, Pilling MJ, Shalashilin DV, Martínez-Núñez E. Classical, quantum and statistical simulations of vibrationally excited HOSO2: IVR, dissociation, and implications for OH + SO2kinetics at high pressures. Phys Chem Chem Phys 2009; 11:963-74. [DOI: 10.1039/b816108a] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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