An experimental study of the reactivity of the hydroxide anion in the gas phase at room temperature, and its perturbation by hydration

Flowing afterglow measurements are reported which provide rate constants and product identifications at 298 ± 2 K for the gas-phase reactions of OH− with CH3OH, C2H5OH, CH3OCH3, CH2O, CH3CHO, CH3COCH3, CH2CO, HCOOH, HCOOCH3, CH2=C=CH2, CH3—C≡CH, and C6H5CH3. The main channels observed were proton transfer and solvation of the OH−. Hydration with one molecule of H2O was observed either to reduce the rate slightly and lead to products which are the hydrated analogues of the "nude" reaction, or to stop the reaction completely, k ≤ 10−12 cm3 molecule−1 s−1. The reaction of OH−•H2O with CH3—C≡CH showed an uncertain intermediate behaviour.

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Gas-phase proton-transfer reactions of the hydronium ion at 298 K

Canadian Journal of Chemistry ◽

10.1139/v79-248 ◽

1979 ◽

Vol 57 (12) ◽

pp. 1518-1523 ◽

Cited By ~ 32

Author(s):

Gervase I. Mackay ◽

Scott D. Tanner ◽

Alan C. Hopkinson ◽

Diethard K. Bohme

Keyword(s):

Proton Transfer ◽

Gas Phase ◽

Rate Constants ◽

Transfer Reactions ◽

Flowing Afterglow ◽

Hydronium Ion ◽

Proton Transfer Reactions

Rate constants measured with the flowing afterglow technique at 298 ± 2 K are reported for the proton-transfer reactions of H3O+ with CH2O, CH3CHO, (CH3)2CO, HCOOH, CH3COOH, HCOOCH3, CH3OH, C2H5OH, (CH3)2O, and CH2CO. Dissociative proton-transfer was observed only with CH3COOH. The rate constants are compared with the predictions of various theories for ion–molecule collisions. The protonation is discussed in terms of the energetics and mechanisms of various modes of dissociation.

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An experimental study for rate constants of the gas phase reactions of CH3CH2OOH with OH radicals, O3, NO2 and NO

Atmospheric Environment ◽

10.1016/j.atmosenv.2008.04.033 ◽

2008 ◽

Vol 42 (27) ◽

pp. 6614-6619 ◽

Cited By ~ 13

Author(s):

Caixia Wang ◽

Zhongming Chen

Keyword(s):

Experimental Study ◽

Gas Phase ◽

Rate Constants ◽

Oh Radicals ◽

Gas Phase Reactions

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The gas phase reactions of the trichloromethylium ion with alkyl aromatics, studied by high pressure mass spectrometry

Canadian Journal of Chemistry ◽

10.1139/v85-433 ◽

1985 ◽

Vol 63 (10) ◽

pp. 2608-2613 ◽

Cited By ~ 3

Author(s):

John Alfred Stone ◽

Nancy Joan Moote ◽

Anastasia C. M. Wojtyniak

Keyword(s):

Mass Spectrometry ◽

High Pressure ◽

Proton Transfer ◽

Gas Phase ◽

Rate Constants ◽

Negative Temperature ◽

Specific Rate ◽

Gas Phase Reactions ◽

Temperature Coefficients ◽

Primary Products

The reactions of trichloromethylium (CCl3+) with benzene and the lower alkyl aromatics (ArH) have been studied by high pressure mass spectrometry at pressures in the range 2–4 Torr and temperatures from 300 to 560 K. The only two primary products are the adduct ArHCCl3+ and ArCCl2+, which is formed by loss of HCl from the adduct. The relative yields of adduct increase with increasing number of methyl substituents on the aromatic ring (benzene → mesitylene). The disappearance of CCl3+ is kinetically second order with specific rate constants increasing from benzene to mesitylene, the latter reacting essentially at every ion–molecule collision. All rate constants are fairly large (>1010 cc molecule−1 s−1) and show negative temperature coefficients. ArCCl2+ is unreactive but ArHCCl3+ reacts further by proton transfer to ArH.

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The Mechanism(S) of the Addition of Alcohols to Protonated Acetone in the Gas-Phase

Australian Journal of Chemistry ◽

10.1071/ch9860839 ◽

1986 ◽

Vol 39 (6) ◽

pp. 839 ◽

Cited By ~ 3

Author(s):

JC Sheldon ◽

GJ Currie ◽

JH Bowie

Keyword(s):

Proton Transfer ◽

Transition State ◽

Gas Phase ◽

Cyclotron Resonance ◽

Transfer Reaction ◽

Proton Transfer Reaction ◽

The Other ◽

Ion Cyclotron Resonance ◽

Gas Phase Reactions ◽

Flowing Afterglow

The gas phase reactions of the systems Me2C=+OH/ROH (R = Me and Pri ) have been investigated by using a combination of experimental [ion cyclotron resonance ( i.c.r .) and flowing afterglow ( f.a .)] and ab initio (4-31G, GAUSSIAN 82) methods. A stabilized adduct, thought to correspond to Me2C=+OH...O(H)R, is observed when R = Pri but not for Me. Decomposing forms of adducts eliminate water; 18O labelling shows the major (overall) reaction to be Me2C=+OH+R18OH → Me2C=+(18O)R+H2OAb initio calculations indicate ( i ) that the product ion in this reaction is produced by two channels, both proceeding through Me2(HO)C-+O(H)R; one directly, the other indirectly through Me2C=+OH...O(H)R, and (ii) that the transition state for the key proton transfer reaction Me2(HO)C-+O(H)Me → Me2( MeO )C-+OH2 is of higher energy than reactants. The latter result suggests that precursor ion Me2C=+O needs to be vibrationally hot for the elimination of water to occur: a comparison of i.c.r . and f.a . experiments confirms this to be the case.

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Methylene. III. Gas phase reactions with 1-chloropropane

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1969.0146 ◽

1969 ◽

Vol 312 (1509) ◽

pp. 141-161 ◽

Cited By ~ 2

Keyword(s):

Gas Phase ◽

Rate Constants ◽

Hydrogen Abstraction ◽

The Other ◽

Gas Phase Reactions ◽

Other Hand ◽

Chlorine Substituent ◽

High Degree ◽

Singlet Methylene

The work described in this and the following paper is a continuation of that in parts I and II, devoted to elucidation of the mechanism of the reactions of methylene with chloroalkanes, with particular reference to the reactivities of singlet and triplet methylene in abstraction and insertion processes. The products of the reaction between methylene, prepared by the photolysis of ketene, and 1-chloropropane have been identified and estimated and their dependence on reactant pressures, photolysing wavelength and presence of foreign gases (oxygen and carbon monoxide) has been investigated. Both insertion and abstraction mechanisms contribute significantly to the over-all reaction, insertion being relatively much more important than with chloroethane. This type of process appears to be confined to singlet methylene. If, as seems likely, there is no insertion into C—Cl bonds under our conditions (see part IV), insertion into C2—H and C3—H bonds occurs in statistical ratio, approximately. On the other hand, the chlorine substituent reduces the probability of insertion into C—H bonds in its vicinity. As in the chloroethane system, both species of methylene show a high degree of selectivity in their abstraction reactions. We find that k S Cl / k S H >7.7, k T Cl / k T H < 0.14, where the k ’s are rate constants for abstraction, and the super- and subscripts indicate the species of methylene and the type of atom abstracted, respectively. Triplet methylene is discriminating in hydrogen abstraction from 1-C 3 H 7 Cl, the overall rates for atoms attached to C1, C2, C3 being in the ratios 2.63:1:0.

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