Thermal chlorine-38 atom reactions with ethylene

Lee, F. S. C.; Rowland, F. S.

doi:10.1021/j100528a004

Cited by 24 publications

(24 citation statements)

References 8 publications

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“…53 These values are not far away from the corresponding QCISD(T)/aug-ccpVDZ//QCISD/6-31G(d,p) values (9.4 and 9.2 kcal/mol, respectively). Therefore, in the case of the abstraction channel, although the PESs predicted by the several methodologies are quite different, all of them seem to be consistent with the reported experimental activation barrier (3-7 kcal/mol) 9-12 and endothermicity (5-6 kcal/mol) 1,8 for this abstraction reaction.…”

Section: Table 1: Most Significant Geometrical Parameters As Computedsupporting

confidence: 86%

Potential Energy Surface for the Chlorine Atom Reaction with Ethylene: A Theoretical Study

et al. 2000

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The potential energy surface of the reaction between chlorine atom and ethylene was explored at the MP2/ 6-31G(d,p), Becke3LYP/6-31G(d,p), QCISD/6-31G(d,p), MP2/6-311+G(d,p), MP2/6-311++G(3df,3pd), and MP2/aug-cc-pVDZ levels of theory. Further QCISD(T)/6-31G(d,p) and QCISD(T)/cc-pVDZ optimizations were performed for some structures of special interest. The geometrical parameters computed for the different structures located on the potential energy surface do not differ too much when employing different methods and basis sets with the only exceptions of those structures involving long distance interactions (van der Waals structures). The pronounced flatness of the potential energy surface in the regions where these structures appear seems to be the responsible for the observed discrepancies. The full optimized QCISD structures tend to become less stable than those computed at the MP2 level, whereas the opposite is true for the Becke3LYP structures. At the MP2 and QCISD levels, the transition structure associated with a direct shuttle motion in the addition channel is too high in energy to be involved in the dissociation mechanism. The existence of two bridged structures Iadd (minimum) and TSadd (transition structure) on the potential energy surface helps to explain the experimentally detected stereochemical control exercised by the chlorine atom in reactions involving haloethyl radicals. Contrarily, the Becke3LYP calculations suggest a mechanism in which the direct shuttle motion could play a relevant role, although the competing mechanism of rotation around the C-C bond is lower in energy. The MP2 and QCISD abstraction channels also differ considerably from the Becke3LYP one. However, in this case all the different potential energy surfaces seem to be consistent with the reported experimental data on the activation energy and endothermicity for the abstraction reaction. The QCISD(T)/ aug-cc-pVDZ//QCISD/6-31G(d,p) relative energies and barrier heights are consistent with the experimental data available on exo/endothermicities and activation barriers for the addition and abstraction reactions.

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Section: Table 1: Most Significant Geometrical Parameters As Computedsupporting

confidence: 86%

Potential Energy Surface for the Chlorine Atom Reaction with Ethylene: A Theoretical Study

et al. 2000

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“…CC12F2, CC13F, CCI4, CH3CI, and CH3CC13, releases chlorine which can then be found among at least five important inorganic chemical species: C1, C10, HC1, HOCl, and C10N02 (chlorine nitrate). The first two are highly reactive odd-electron species capable of producing the CIO, free radical chain of (1) and (2), whose net result is the removal C1 + O3 -C10 + O2 (1) c10 + 0 -CI + 0 2 (2) of odd oxygen (= O3 or 0) from the stratosphere in the altitude range from 30 to 50 km. 'S2 The other three chlorinated compounds are even-electron species which serve as relatively unreactive reservoir molecules, temporarily withholding chlorine from the free radical chain processes.…”

Section: Introductionmentioning

confidence: 99%

“…'S2 The other three chlorinated compounds are even-electron species which serve as relatively unreactive reservoir molecules, temporarily withholding chlorine from the free radical chain processes. The two molecules C10N02 and (1) A full understanding of all of the atmospheric processes affecting these compounds has always been necessary for the modeling of stratospheric chemistry with the intent either of representation as it exists or prediction of possible future changes, e.g. depletion of stratospheric ozone.…”

Section: Introductionmentioning

confidence: 99%

“…We have measured the reaction rate constants for chlorine atoms with H2S by (1) over the temperature range from 232 to 3sCl + H2S -H38C1 + SH (1) 359 K utilizing a competitive radiochemical technique at pressures of approximately 4000 Torr.I4 The reaction of chlorine atoms with H2S is potentially important in the atmosphere of the earth and of other planets.56 Several previous experiments have provided measurements of the reaction rate constant at 298 K ranging from…”

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The hydrolysis of chlorine nitrate and its possible atmospheric significance

Rowland¹,

Sato²,

Khwaja³

et al. 1986

J. Phys. Chem.

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The hydrolysis of C10N02 takes place very readily on a variety of laboratory surfaces and may also occur catalytically on particulate surfaces in the stratosphere. The reaction can be considered as an oxide exchange between two X-O-Y molecules with X and Y = H, Cl, or N02. Two other reactions in this class which might occur in the stratosphere are HOC1 plus HOC1, and HOC1 plus C10N02. Each of these three is approximately thermoneutral and should be accompanied by the reverse reaction with a comparable reaction rate constant. Current atmospheric models have not explained the very large ozone depletions which have taken place during Antarctic spring in the past decade. The chemical reactions included in these models may need to include heterogeneous catalysis of one or more of these oxide exchange reactions.

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“…Energy degraded hot atoms are produced that, in the absence of open epithermal reaction Channels, may achieve thermal equilibrium with molecules of the host reservoir [1,2]. Moderated nuclear recoil techniques have thus been utilized in investigations of atomic halogen reactions under conditions of thermal Initiation [1][2][3][4][5][6][7].…”

Section: Introductionmentioning

confidence: 99%

Steady State Kinetic Theory Model Calculations

Knierim¹,

Root

1977

Radiochimica Acta

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Atomic Fluorine/Fluorine-18/Hot atom chemistry reactions/ Hot atom theory !Moderator effects /Hot atom energetics AbstractWith the aid of the steady State kinetic theory of hot atom reactions, the dynamical and approximate energetics characteristics of the nuclear recoil'" F + H, process have been determined as a function of Ar additive concentration. The addition of Ar causes an increase in the rate of coohng of the hot atom momentum density distribution, leading to reduction of the nonthermal reaction yield. Except in the low reactivity limit the average reactive collision energy decreases, whereas the average nonthermal reactive lifetime inaeases accompanying the addition of moderator. Thermal or epithermal reaction contamination may interfere in moderated nuclear recoil experiments unless the hot reaction is thermally inaccessible.

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Thermal chlorine-38 atom reactions with ethylene

Cited by 24 publications

References 8 publications

Potential Energy Surface for the Chlorine Atom Reaction with Ethylene: A Theoretical Study

Potential Energy Surface for the Chlorine Atom Reaction with Ethylene: A Theoretical Study

The hydrolysis of chlorine nitrate and its possible atmospheric significance

Steady State Kinetic Theory Model Calculations

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