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

1985 ◽  
Vol 63 (10) ◽  
pp. 2608-2613 ◽  
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.

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

1981 ◽  
Vol 59 (11) ◽  
pp. 1615-1621 ◽  
Author(s):  
Scott D. Tanner ◽  
Gervase I. Mackay ◽  
Diethard K. Bohme
Keyword(s):  
Experimental Study ◽  
Proton Transfer ◽  
Gas Phase ◽  
Rate Constants ◽  
Room Temperature ◽  
Gas Phase Reactions ◽  
Flowing Afterglow ◽  
Hydroxide Anion

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.

Kinetics and Rate Constants of Reactions Leading to Hydration of and in Gaseous Oxygen, Argon, and Helium Containing Traces of Water

1972 ◽  
Vol 50 (14) ◽  
pp. 2230-2235 ◽  
Author(s):  
J. D. Payzant ◽  
A. J. Cunningham ◽  
P. Kebarle
Keyword(s):  
High Pressure ◽  
Electron Beam ◽  
Gas Phase ◽  
Mass Spectrometer ◽  
Rate Constants ◽  
Gas Phase Reactions ◽  
Third Order ◽  
Gaseous Oxygen ◽  
Time Resolved ◽  
Pulsed Electron Beam

The rate constants for the forward and reverse components of gas phase reactions:[Formula: see text]were measured with a pulsed electron beam, time resolved detection high pressure mass spectrometer at 300 °K. O2, Ar, and He at pressures from 1–7 Torr were used as third gas M. The forward reactions were found to be third order and the reverse reactions second order. Establishment of the equilibria could also be observed.

The reactions of trichloromethylium with oxygen- and sulfur-containing compounds

1986 ◽  
Vol 64 (12) ◽  
pp. 2447-2455 ◽  
Author(s):  
John Alfred Stone ◽  
Nancy Joan Moote
Keyword(s):  
Mass Spectrometry ◽  
Gas Phase ◽  
Rate Constants ◽  
Photoelectron Spectroscopy ◽  
Cyclic Ethers ◽  
Measurable Effect ◽  
Gas Phase Reactions ◽  
Diethyl Ketone ◽  
Sulfur Containing ◽  
Sulfur Containing Compounds

The gas phase reactions of CCl3+ with acetone, diethyl ketone, dimethyl ether, diethyl ether, several cyclic ethers, sulfides, and disulfides have been examined using high pressure mass spectrometry. In many of the reactions a stabilized ion–molecule complex is observed which may or may not react further. With disulfides a second reaction channel is electron transfer, the observation of which shows that the 0–0 ionization energies of these compounds are lower than the ionization energy of CCl3 (8.28 eV) and hence lower than the values obtained by photoelectron spectroscopy. Rate constants for the disappearance of CCl3+ in general show an increase in value with increase in reaction exothermicity. The lack of a measurable effect of pressure on rate constants is discussed for some association reactions which have reaction efficiencies well below unity.

Methylene. III. Gas phase reactions with 1-chloropropane

1969 ◽  
Vol 312 (1509) ◽  
pp. 141-161 ◽  
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.

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

1979 ◽  
Vol 57 (12) ◽  
pp. 1518-1523 ◽  
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.

Rate Constants for the Gas-Phase Reactions of Methylphenanthrenes with OH as a Function of Temperature

2003 ◽  
Vol 107 (34) ◽  
pp. 6603-6608 ◽  
Author(s):  
Woojin Lee ◽  
Philip S. Stevens ◽  
Ronald A. Hites
Keyword(s):  
Gas Phase ◽  
Rate Constants ◽  
Gas Phase Reactions

Five vs Six Membered-Ring PAH Products from Reaction of o-Methylphenyl Radical and two C3H4 Isomers

2021 ◽  
Author(s):  
Oisin J Shiels ◽  
Matthew Brian Prendergast ◽  
John Savee ◽  
David L Osborn ◽  
Craig A. Taatjes ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Phase ◽  
Membered Ring ◽  
Gas Phase Reactions

Gas-phase reactions of the o-methylphenyl (o-CH3C6H4) radical with the C3H4 isomers allene (H2C=C=CH2) and propyne (HCºC-CH3) are studied at 600 K and 4 Torr (533 Pa) using VUV synchrotron photoionisation mass spectrometry,...

Collision-induced elimination of alkenes from deprotonated unsaturated ethers in the gas phase. Reactions involving specific .beta.-proton transfer

1990 ◽  
Vol 112 (7) ◽  
pp. 2537-2541 ◽  
Author(s):  
Russell J. Waugh ◽  
Roger N. Hayes ◽  
Peter C. H. Eichinger ◽  
K. M. Downard ◽  
John H. Bowie
Keyword(s):  
Proton Transfer ◽  
Gas Phase ◽  
Gas Phase Reactions
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