Concentration enrichment in the ion source of a pulsed electron beam high pressure mass spectrometer

1994 ◽  
Vol 139 ◽  
pp. 47-58 ◽  
Author(s):  
D.S. McGrew ◽  
W.B. Knighton ◽  
J.A. Bognar ◽  
E.P. Grimsrud
Keyword(s):  
High Pressure ◽  
Electron Beam ◽  
Mass Spectrometer ◽  
Ion Source ◽  
Pulsed Electron Beam

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 gas phase reactivity of the dimethylchloronium ion with alkylbenzenes

1981 ◽  
Vol 59 (15) ◽  
pp. 2412-2416 ◽  
Author(s):  
John A. Stone ◽  
Margaret S. Lin ◽  
Jeffrey Varah
Keyword(s):  
High Pressure ◽  
Gas Phase ◽  
Mass Spectrometer ◽  
Aromatic Hydrocarbons ◽  
Relative Rate ◽  
Ion Source ◽  
Nucleophilic Displacement ◽  
Rate Of Reaction ◽  
Displacement Reactions ◽  
Bonded Complexes

The reactivity of the dimethylchloronium ion with a series of aromatic hydrocarbons has been studied in a high pressure mass spectrometer ion source using the technique of reactant ion monitoring. Benzene is unreactive but all others, from toluene to mesitylene, react by CH3+ transfer to yield σ-bonded complexes. The relative rate of reaction increases with increasing exothermicity in line with current theories of nucleophilic displacement reactions.

The formation of (CH3)7Si2+ in (CH3)4Si/CH4 mixtures and CH3− exchange reactions between (CH3)4Si, (CH3)4Ge, and (CH3)4Sn studied by high pressure mass spectrometry

1987 ◽  
Vol 65 (12) ◽  
pp. 2849-2854 ◽  
Author(s):  
Anastasia C. M. Wojtyniak ◽  
Xiaoping Li ◽  
John A. Stone
Keyword(s):  
Mass Spectrometry ◽  
High Pressure ◽  
Equilibrium Constant ◽  
Mass Spectrometer ◽  
Excellent Agreement ◽  
Ion Source ◽  
Methyl Groups ◽  
Exchange Reactions ◽  
Equilibrium Reactions ◽  
Association Equilibrium

The association equilibrium [Formula: see text] has been studied in a high pressure mass spectrometer ion source using tetramethylsilane/methane mixtures. Measurement of the equilibrium constant over a range of temperatures yields ΔH0 = −22.3 ± 0.4 kcal mol−1 and ΔS0 = −35.2 ± 0.9 cal mol−1 K−1. Collision-assisted dissociation experiments suggest that the methyl groups retain their integrity in (CH3)7Si2+. Mixed ions such as (CH3)7SiGe+ and (CH3)7GeSn+ were not observed in mixtures of (CH3)4X and (CH3)4Y(X ≠ Y = Si, Ge, Sn). Instead CH3− transfer equilibrium reactions were observed viz. [Formula: see text] (ΔH0 = −10.2 ± 1.2 kcal mol−1, ΔS0 = −3.7 ± 2.4 cal K−1 mol−1) and [Formula: see text], ΔS0 = −0.9 ± 1.6 cal K−1 mol−1. These are in excellent agreement with some published differences in appearance potentials for (CH3)3X+ from (CH3)4X (X = Si, Ge, Sn).

Investigation of the propagation of a gigawatt pulsed electron beam in compositions of high-pressure gas

2014 ◽  
Vol 21 (7) ◽  
pp. 072302 ◽  
Author(s):  
R. V. Sazonov ◽  
G. E. Kholodnaya ◽  
D. V. Ponomarev ◽  
G. E. Remnev
Keyword(s):  
High Pressure ◽  
Electron Beam ◽  
Pulsed Electron Beam

A mass spectrometer for studying chemical reactions

1963 ◽  
Vol 274 (1358) ◽  
pp. 285-292 ◽  
Keyword(s):  
Electron Beam ◽  
Gas Phase ◽  
Mass Spectrometer ◽  
Ion Source ◽  
Line Of Sight ◽  
Pyrolysis Products ◽  
Ionization Region ◽  
Differential Pumping ◽  
Hot Filament ◽  
Phase Chemical

This paper describes a mass spectrometer designed to study gas-phase chemical kinetics. An ion source has been constructed which incorporates a differentially pumped, electron beam filament chamber, and line-of-sight access from the sampling pinhole to the ionization region. Experiments are described which test the effectiveness of differential pumping in reducing contamination of the sample by pyrolysis products formed from the sample on the hot filament.

The binding energies of trialkylgermanium cations to water molecules studied by high pressure mass spectrometry

1987 ◽  
Vol 65 (9) ◽  
pp. 2146-2148 ◽  
Author(s):  
John Alfred Stone ◽  
Wilhelmus Johannes Wytenburg
Keyword(s):  
Mass Spectrometry ◽  
High Pressure ◽  
Electron Beam ◽  
Binding Energy ◽  
Thermodynamic Data ◽  
Binding Energies ◽  
Water Molecules ◽  
Pulsed Electron Beam

The binding energies of H2O to R3Ge+ have been measured using pulsed electron beam, high pressure mass spectrometry. van't Hoff plots have yielded thermodynamic data (ΔH0, ΔS0) for the reactions, [5], [Formula: see text]and [7], [Formula: see text]. [Formula: see text] decreases with increasing size of R (CH3 28.6 ± 0.5 kcal mol−1, C4H9 20.6 ± 1.2 kcal mol−1) while [Formula: see text] shows much less change (34.4 ± 0.9 to 30.3 ± 2.8 cal K−1 mol−1). Comparison with data for (CH3)3M+ (M = Si, Sn) shows that binding energy decreases with increasing size of M.

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