Influence of chlorine substitution on the rate of oxidation of paraffin hydrocarbons

In the kinetics of their gas phase oxidations primary and some secondary chloro-paraffins are generally similar to the corresponding hydrocarbons. The rate is strongly affected by the pressure of the organic reactant and nearly independent of oxygen. (With tertiary chloro-compounds an oxygen-catalyzed pyrolysis obscures the direct oxidation.) For the oxidation a mechanism analogous to that proposed for hydrocarbons is assumed, namely one in which the rate is governed by branching chains whose development depends upon the breaking of an unstable —O—O— link. Previous work on the influence of hydrocarbon structure is interpreted with the aid of the hypothesis that methyl groups exert a specific stabilizing effect (and that relatively rapid oxidation demands a point of attack in the molecule sufficiently remote from a methyl group). In the light of this hypothesis the influence of chlorine atoms is compared with that of methyl groups. The chlorine accelerates the oxidation ( a ) by impairing the symmetry of a methyl group into which it is introduced, and ( b ) by a direct inductive effect of its own. The opposite effects of chlorine and of methyl are consistent with the view that the —O—O— links are stabilized by electron accession and weakened by electron recession.

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Kinetics of the gas phase reaction of chlorine atoms with a series of alkenes, alkynes and aromatic species at 295 K

Journal of Photochemistry and Photobiology A Chemistry ◽

10.1016/1010-6030(88)80126-6 ◽

1988 ◽

Vol 45 (2) ◽

pp. 167-175 ◽

Cited By ~ 49

Author(s):

Timothy J. Wallington ◽

Loretta M. Skewes ◽

Walter O. Siegl

Keyword(s):

Gas Phase ◽

Phase Reaction ◽

Chlorine Atoms ◽

Gas Phase Reaction ◽

Aromatic Species ◽

Kinetics Of

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Kinetics of the Gas-Phase Reactions of Chlorine Atoms with Naphthalene, Acenaphthene, and Acenaphthylene

The Journal of Physical Chemistry A ◽

10.1021/jp5009434 ◽

2014 ◽

Vol 118 (20) ◽

pp. 3535-3540 ◽

Cited By ~ 9

Author(s):

Matthieu Riva ◽

Robert M. Healy ◽

Pierre-Marie Flaud ◽

Emilie Perraudin ◽

John C. Wenger ◽

...

Keyword(s):

Gas Phase ◽

Gas Phase Reactions ◽

Chlorine Atoms ◽

Kinetics Of

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Radical stabilization energies : The β-alkoxy group from kinetics of the thermal isomerization of 1-Chloro-4-methoxymethylbicyclo[2,2,0]hexane in the gas and liquid phase

Australian Journal of Chemistry ◽

10.1071/ch9721443 ◽

1972 ◽

Vol 25 (7) ◽

pp. 1443 ◽

Cited By ~ 6

Author(s):

EN Cain ◽

RK Solly

Keyword(s):

Gas Phase ◽

Inductive Effect ◽

Diphenyl Ether ◽

Thermal Isomerization ◽

Alkoxy Group ◽

Ether Oxygen Atom ◽

Ether Oxygen ◽

Stabilization Energies ◽

Electronegative Atom ◽

Kinetics Of

The kinetics of the thermal isomerization of 1-chloro-4-methoxymethyl- log(kb/s-1) = (14.1 � 0.2)-(36.2 � 0.5)/θwhere θ = 2.303RT kcal/mol and the subscripts g, a, and b refer to the gas phase, nitrobenzene-d5 as solvent, and diphenyl ether as solvent respectively. The Arrhenius parameters are discussed in terms of transition state estimates for a biradical mechanism. With reference to the isomerization of bicyclo[2,2,0]hexane and 1,4 dichlorobicyclo[2,2,O]hexane, the α-methoxymethyl group is shown to destabilize the biradical by 6.1 � 2.4 kcal/mol by comparison with an α-propyl group. This radical destabilization by the β-ether oxygen atom is explained in terms of the inductive effect of the β-electronegative atom.

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Determination of the gas-phase value of the inductive effect parameter of the methyl group from solvatochromic study of the charge-transfer band maxima of complexes of tetracyanoethylene with methylbenzenes

Journal of Chemical Sciences ◽

10.1007/bf02867597 ◽

1994 ◽

Vol 106 (1) ◽

Author(s):

Mahadeb Roy ◽

Bejoy K Seal

Keyword(s):

Charge Transfer ◽

Gas Phase ◽

Inductive Effect ◽

Charge Transfer Band ◽

Methyl Group ◽

Effect Parameter

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X+ transfer from the halonium ions of adamantylideneadamantane to acceptor olefins. The possibility of chiral induction in the transfer process

Canadian Journal of Chemistry ◽

10.1139/v97-617 ◽

1997 ◽

Vol 75 (12) ◽

pp. 1844-1850 ◽

Cited By ~ 3

Author(s):

Alexei A. Neverov ◽

Theresa L. Muise ◽

R.S. Brown

Keyword(s):

Nmr Spectra ◽

Room Temperature ◽

Reaction Rate ◽

Methyl Groups ◽

Kinetic Behavior ◽

Methyl Group ◽

Chiral Induction ◽

H Nmr ◽

Group 12 ◽

Kinetics Of

The bromonium ion of adamantylideneadamantane (Ad=Ad-Br+) has been used to induce the bromocyclization of a 4-pentenyl glycoside (10) and a 5-hexenyl glycoside (11) in dichloroethane. The kinetics of these processes have been studied at 25 °C in the presence of varying [Ad=Ad] and, in the case of the transfer to 10, in the presence of pentanol. The second-order rate constants for bromocyclization of these two alkenes are (1.04 ± 0.06) × 10−1 M−1 s−1 and (5.34 ± 0.2) × 10−1 M−1 s−1, respectively, and in no case does added Ad=Ad or pentanol alter the reaction rate. The kinetic behavior is interpreted in terms of cyclization occurring directly from a 1:1 complex of Ad=Ad-Br+ and 10 or 11. The chiral induction for the bromocyclization of 10 promoted by AdAd-Br+ was measured at 20% e.e., the (−)-(S)-tetrahydrofurfuryl bromide being the dominant stereoisomer. Ad=Ad molecules substituted at one of the homoallylic carbons by an axial methyl group (12), or by two methyl groups (axial and equatorial), were synthesized and the 1H NMR spectra of their bromonium ions is given. These materials are not stable for prolonged times at room temperature. A limited kinetic study of the reaction of 12-Br+ and 4-pentenol indicated that the Br+ transfer is 500 times faster than the comparable transfer from Ad=Ad-Br+ to 4-pentenol. The possibility of using these materials to induce chiral bromocyclization is discussed. Keywords: bromonium ion, halonium, transfer, chiral, adamantylideneadamantane.

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