Energy dependence of ion-molecule reactions. II. Methyl chloride

1969 ◽  
Vol 22 (11) ◽  
pp. 2275 ◽  
Author(s):  
NA McAskill
Keyword(s):  
Energy Range ◽  
Gas Phase ◽  
Energy Dependence ◽  
Mass Spectrometer ◽  
Rate Constant ◽  
Methyl Chloride ◽  
Negative Ion ◽  
Polar Molecules ◽  
Ion Energy ◽  
Ion Molecule Reactions

The ion-molecule reactions of ions in methyl chloride were studied in the gas phase at source pressures of up to 120 μ in a mass spectrometer using ions having exit energies which ranged from 0.2 to 2.0 eV. The ions produced by secondary processes included CH4Cl+, CH2Cl+, and C2H6Cl+. The rate constant for the reaction of CH3Cl+ was found to be independent of the ion energy in the energy range studied. A theoretical rate constant which is independent of the ion energy was also derived for reactions between ions and polar molecules. Negative ion spectra were briefly examined.

scholarly journals Ruthenium trisbipyridine as a candidate for gas-phase spectroscopic studies in a Fourier transform mass spectrometer

2004 ◽  
Vol 18 (2) ◽  
pp. 387-396 ◽  
Author(s):  
Jill R. Scott ◽  
Jason E. Ham ◽  
Bill Durham ◽  
Paul L. Tremblay
Keyword(s):  
Fourier Transform ◽  
Gas Phase ◽  
Mass Spectrometer ◽  
Rate Constant ◽  
Optical Detection ◽  
Sinapinic Acid ◽  
Spectroscopic Studies ◽  
Fluorescence Lifetimes ◽  
Fourier Transform Mass Spectrometer

Metal polypyridines are excellent candidates for gas-phase optical experiments where their intrinsic properties can be studied without complications due to the presence of solvent. The fluorescence lifetimes of [Ru(bpy)3]1+trapped in an optical detection cell within a Fourier transform mass spectrometer were obtained using matrix-assisted laser desorption/ionization to generate the ions with either 2,5-dihydroxybenzoic acid (DHB) or sinapinic acid (SA) as matrix. All transients acquired, whether using DHB or SA for ion generation, were best described as approximately exponential decays. The rate constant for transients derived using DHB as matrix was 4×107s−1, while the rate constant using SA was 1×107s−1. Some suggestions of multiple exponential decay were evident although limited by the quality of the signals. Photodissociation experiments revealed that [Ru(bpy)3]1+generated using DHB can decompose to [Ru(bpy)2]1+, whereas ions generated using SA showed no decomposition. Comparison of the mass spectra with the fluorescence lifetimes illustrates the promise of incorporating optical detection with trapped ion mass spectrometry techniques.

Negative ion–molecule reactions in liquid argon following electron capture by N2O

1977 ◽  
Vol 55 (11) ◽  
pp. 2220-2224 ◽  
Author(s):  
George Bakale ◽  
Ulrich Sowada ◽  
Werner F. Schmidt
Keyword(s):  
Electron Capture ◽  
Rate Constant ◽  
Liquid Argon ◽  
Negative Ion ◽  
X Rays ◽  
Electron Current ◽  
Short Burst ◽  
Bimolecular Rate Constant ◽  
Ion Molecule Reactions

Electrons produced in liquid argon by a short burst of X rays react readily with dissolved N2O with a bimolecular rate constant of 5.8 × 10−10 cm3/s or 3.5 × 1011 M−1 s−1. The addition of H2 or CO to the Ar/N2O solution results in a fast and slower component in the decay of the electron current. We assume that O− ions are formed in the reaction of electrons with N2O and then react with H2 to give[Formula: see text]or with CO to give[Formula: see text]The addition of CH4 does not regenerate electrons since the reaction[Formula: see text]is thought to occur. Reaction 12 is in agreement with the fact that CO2 does not react with electrons in liquid argon.

Energy dependence of ion-molecule reactions. I. Methane

1969 ◽  
Vol 22 (11) ◽  
pp. 2267 ◽  
Author(s):  
NA McAskill
Keyword(s):  
Proton Transfer ◽  
Energy Dependence ◽  
Cross Section ◽  
Mass Spectrometer ◽  
Transfer Reaction ◽  
Proton Transfer Reaction ◽  
Ion Chamber ◽  
Ion Molecule Reactions ◽  
Path Lengths ◽  
Primary Ions

The ion-molecule reactions of gaseous methane were studied at source pressures of up to 70 μ using a mass spectrometer operated without the usual source magnets. The range of ion exit energies used (0.2-1.8 eV) was obtained by using different ion path lengths as well as different field strengths. The operation of the mass spectrometer was checked by measuring the rate for the proton transfer reaction of CH4+. The energy dependence and the rate of the reactions inside the ion chamber of all the primary ions in CH4 were determined by plotting the cross section against the term, (ion exit energy)-1/2.

Ion-molecule reactions in Trihalo- and Tetrahalo-methanes

1970 ◽  
Vol 23 (5) ◽  
pp. 893 ◽  
Author(s):  
NA McAskill
Keyword(s):  
Gas Phase ◽  
Cross Sections ◽  
High Pressures ◽  
Rate Coefficients ◽  
Ion Transfer ◽  
Ion Energy ◽  
Transfer Processes ◽  
Ion Molecule Reactions ◽  
Ionic Systems ◽  
Derivatives Of

The ion-molecule reactions of eight highly halogenated derivatives of methane were studied in the gas phase using a mass spectrometer operated at high pressures. The compounds studied were CHCl3, CHCl2F, CHClF2, CHF3, CCl4, CCl2F2, CClF3, and CF4. These ionic systems were found to be less reactive than those of methane or the methyl and methylene halides. The main reactions observed were described as being halide ion transfer processes. The energy dependence of the cross sections and the rate coefficients of the reactant ions were determined.� Many rate coefficients for reactions between ions and polar molecules were found to be independent of the ion energy. Brief studies of the negative spectra at high pressures were also made.

Gas-phase positive and negative ion/molecule reactions in diborane and silane/diborane mixtures

2007 ◽  
Vol 264 (1) ◽  
pp. 61-69 ◽  
Author(s):  
Lorenza Operti ◽  
Roberto Rabezzana ◽  
Francesca Turco ◽  
Gian Angelo Vaglio
Keyword(s):  
Gas Phase ◽  
Negative Ion ◽  
Ion Molecule Reactions
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