Reactions of thermal energy ions. VI. Hydrogen-transfer ion–molecule reactions involving polar molecules

Abstract

The rate constants for formation of the protonated molecule by ion–molecule reactions in CH3OH, (CH3)2O, and CH4 have been studied both at thermal energies and at 3.4 eV ion exit energy with a new mass spectrometer described in the present work. The rate constants are found to be approximately a factor of two greater than previously measured and it is concluded that an error in pressure measurement was made in the earlier work. Revised rate constants are presented for a number of systems studied previously. The results are compared with predictions of the collision theory modified in this paper to include the effect of ion-dipole interactions.

Ion–molecule reactions in formic-d acid and methyl formate

“…The pressure studies and the ratio plot studies reported below were carried out using the medium pressure instrument recently described (5). The pertinent operating conditions were a source temperature of approximately 100 "C, a primary ion travel distance of 0.54 cm, and a constant repeller field corresponding to 2.4 eV ion exit energy.…”

“…The pertinent operating conditions were a source temperature of approximately 100 "C, a primary ion travel distance of 0.54 cm, and a constant repeller field corresponding to 2.4 eV ion exit energy. The electron beam was pulsed and primary ion residence times were measured by the deflection technique previously described (5). The source pressures were measured directly with an MKS Baratron micromanometer.…”

Radiation chemistry and mass spectrometry of silanes and germanes. Progress report, June 1, 1972--May 31, 1973

“…diameter tubing to the ion-source. The pressure-dependent formation of CHs , which occurs in CH4 -CH4 collisions with a known specific reaction rate, indicated the pressure'readings to be accurate to within [9][10][11][12] t10%·…”

Influence of Repeller Potential on Ion-Molecule Reactions in H2S and CH4Mixtures

“…Investigations of ion-molecule reactions in pure hydrogen sulfide [1][2][3][4][5][6] and methane [7][8][9][10][11][12][13][14][15] and also in the mixture of H 2 S with CH 4 were performed using various mass spectrometric techniques and methods [16][17][18][19].…”