The Energy Dependence of Cross Sections of Some Ion-Molecule Reactions

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.

Section: The Formation Of Cc13+supporting

confidence: 65%

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

Stone¹,

Moote²,

Wojtyniak³

1985

“…However, mass spectroinetric studies show that the primary ion, C H 3 0 H + , can undergo ion molecule reactions 1 and 2 with alinost equal probability (2)(3)(4).…”

Section: Introductionmentioning

confidence: 99%

The Detection of Alkoxy and Other Radicals in the Gamma Radiolysis of Alcohols by an Electron Spin Resonance and Spin Trapping Method

Sargent¹,

Gardy²

1974

FREDERICK PETER SARGEKT and EDWARD M~CHAEL CARDY. Can. J. Chem. 52,3645 (1974). The radicals produced during y radiolysis of methanol, ethanol, I-propanol, 2-propanol, and t-butanol have been trapped by reaction with 2-nitroso-2-niethylpropane (t-nitrosobutane) to give nitroxides which are detected by e.s.r.All the alcohols gave alkoxy radicals and, with the exception of t-butanol, radicals derived by the loss of an H atom from the carbon atom adjacent to the OH group. Methyl radicals were detected in t-butanol.FREDERICK PETER SARGENT et EDWARD MICHAEL GARDY. Can. J. Chem. 52,3645 (1974). On a piege les radicaux produits loss de la radiolyse gamma du methanol, de l'ethanol, du propanol-I, du propanol-2, et du rerr-butanol avec du nitroso-2 methyle-2 propane (rerr-nitrosobutane) qui conduisent a des radicaux nitroxydes q~~i peuvent Etre detectes par r.p.e. R . + t-BuNO + t-BUN-R

“…I t is possible that reaction [12] is occurring a t higher electron energies. This could not be determined since it was not possible to obtain conditions such that 1 Within experimental error A(C4HSf) coillcided with il(C3H3+), thus eliminating significant contributions from reactions [14], [15], [19], and [20]. However, the ratio I j 3 / 1 3 9 was found to decrease wit11 decreasi~lg electron energy near the appearance potential threshold, suggesting a secoild reaction of higher appearance potential.…”

Section: Ion-~lfolec~ile Reactionsmentioning

confidence: 99%

“…Theard and Hamill (1) have poiilted out in a recent communication that many of the cross sections reported in the literature for ion-molecule reactioils inust be coilsidered as suspect. This arises because the method of identification of the reactant ion by measurement of the secondary ion appearance potential only provides information on the reaction of lowest appearance potential.…”

Section: Introductionmentioning

confidence: 99%

Concurrent Ion–molecule Reactions Leading to the Same Production

Harrison¹,

Tait²

1962

Seven of the major secondary ions in the high-pressure mass spectrunl of cyclopropane have been studied. A method has been developed for studying concurrent ion-molecule reactions and it has been shown that four of the secondary ions are the products of more than one reaction. Cross sections for the separate reactions are reported. The appearance potentials of the major primary ions in the mass spectrum of cyclopropane have been measured: