Bimolecular Reactions of Trapped Ions. VIII. Reactions in Propane and Propane–Methane Mixtures

1974 ◽  
Vol 52 (9) ◽  
pp. 1798-1806 ◽  
Author(s):  
Bruce H. Solka ◽  
Andrew Y.-K. Lau ◽  
Alex. G. Harrison
Keyword(s):  
Rate Constant ◽  
Trapped Ions ◽  
Ion Trapping ◽  
Rate Coefficients ◽  
Collision Rate ◽  
Bimolecular Reactions ◽  
Ion Molecule Reactions ◽  
Product Ions ◽  
Primary Ions

The ion-molecule reactions in propane and in methane–propane mixtures have been studied using an ion-trapping technique and rate coefficients have been measured for the reactions occurring. In pure propane the C2H5+ primary ions react by H− transfer to form C3H7+ whereas C2H4+ reacts to form C3H6+ (25%) and C3H7+ (75%). Using isotopically labelled propanes it was found that both n-propyl and i-propyl ions were formed with the n-propyl ions reacting slowly to produce i-propyl ions. In various deuterium labelled methane–propane mixtures C(H,D)5+ reacts with the propane with a rate constant of ∼1.5 × 10−9 cm3 molecule−1 s−1 in agreement with the calculated collision rate. It is shown that no hydrogens from the CH5+ ion are incorporated in the product ions which are found to be C2H5+ (70%), (CH3)2CH+ (25%), and CH3CH2CH2+ (5%).

scholarly journals Bimolecular Reactions of Trapped Ions. VI. Ion–Molecule Reactions Involving CH5+ and C2H5+

1973 ◽  
Vol 51 (10) ◽  
pp. 1645-1654 ◽  
Author(s):  
A. S. Blair ◽  
A. G. Harrison
Keyword(s):  
Proton Transfer ◽  
Trapped Ions ◽  
Rate Coefficients ◽  
Polar Molecules ◽  
Large Role ◽  
Bimolecular Reactions ◽  
Trapped Ion ◽  
Ion Molecule Reactions ◽  
Dipole Interactions ◽  
Induced Dipole

The ion–molecule reactions in mixtures of methane with the polar molecules dimethyl-d6 ether, ethylene-d4 oxide, acetaldehyde-d4, acetone, and acetonitrile have been studied using the trapped-ion technique. The CH5+ and C2H5+ ions produced by ion–molecule reactions in methane react rapidly (predominantly by proton transfer) with the polar molecules; the rate coefficients range from 1.98 × 10−9 cm3 molecule−1 s−1 (C2H5+ + C2D4O) to 5.26 × 10−9 cm3 molecule−1 s−1 (CH5+ + (CH3)2CO). The rate coefficients are much larger than those predicted from ion – induced dipole interactions only indicating that ion–dipole interactions play a large role in the collision process.Rate coefficients for reaction of CH3+ and CH4+ with the polar molecules also have been measured. Most of these also are larger than predicted from ion – induced dipole interactions indicating in this case as well substantial effects due to ion–dipole interactions.

Ion-molecule reactions of formic acid. I. Proton-transfer reactions

1978 ◽  
Vol 31 (10) ◽  
pp. 2157 ◽  
Author(s):  
CG Freeman ◽  
PW Harland ◽  
MJ McEwan
Keyword(s):  
Proton Transfer ◽  
Formic Acid ◽  
General Equation ◽  
Reasonable Agreement ◽  
Transfer Reactions ◽  
Rate Coefficients ◽  
Collision Rate ◽  
Dipole Orientation ◽  
Ion Molecule Reactions ◽  
Proton Transfer Reactions

Rate coefficients are reported for a number of proton-transfer reactions with formic acid. These reactions can be represented by the general equation �������������������������� XH++HCOOH → (HCOOH)H+ +X : (X = CH4, H2O, N2, CO, HCN, HCHO, CH3OH and H2S). Reasonable agreement was obtained between our observed results and predictions based on the average-dipole-orientation (ADO) model except that ADO theory may slightly underestimate the collision rate.

Reactivity Trends in the Gas Phase Addition of Acetylene to N-protonated Aryl Radical Cations

2020 ◽  
Author(s):  
Oisin Shiels ◽  
P. D. Kelly ◽  
Cameron C. Bright ◽  
Berwyck L. J. Poad ◽  
Stephen Blanksby ◽  
...  
Keyword(s):  
Gas Phase ◽  
Ion Trap ◽  
Radical Cations ◽  
Rate Coefficients ◽  
Similar Process ◽  
Ion Molecule Reactions ◽  
Aromatic Radicals ◽  
Polycyclic Aromatic ◽  
Gas Phase Ion ◽  
Type Radical

<div> <div> <div> <p>A key step in gas-phase polycyclic aromatic hydrocarbon (PAH) formation involves the addition of acetylene (or other alkyne) to σ-type aromatic radicals, with successive additions yielding more complex PAHs. A similar process can happen for N- containing aromatics. In cold diffuse environments, such as the interstellar medium, rates of radical addition may be enhanced when the σ-type radical is charged. This paper investigates the gas-phase ion-molecule reactions of acetylene with nine aromatic distonic σ-type radical cations derived from pyridinium (Pyr), anilinium (Anl) and benzonitrilium (Bzn) ions. Three isomers are studied in each case (radical sites at the ortho, meta and para positions). Using a room temperature ion trap, second-order rate coefficients, product branching ratios and reaction efficiencies are reported. </p> </div> </div> </div>

An ICR mass spectrometry study of ion/molecule reactions between ethyl chloride and alkylamines

1991 ◽  
Vol 69 (2) ◽  
pp. 363-367
Author(s):  
Guoying Xu ◽  
Jan A. Herman
Keyword(s):  
Mass Spectrometry ◽  
Key Words ◽  
Rate Constant ◽  
Rate Constants ◽  
Ethyl Chloride ◽  
Ion Molecule Reactions ◽  
Mass Spectrometry Study ◽  
Ethyl Cation

Ion/molecule reactions in mixtures of ethyl chloride with C1–C4 alkylamines were studied by ICR mass spectrometry. Ethyl cation transfer to C1–C4 alkylamines proceeds mainly through diethylchloronium ions with rate constants ~3 × 10−10cm3 s−1. In the case of s-butylamine the corresponding rate constant is 0.5 × 10−10 cm3 s−1. Key words: ICR mass spectrometry, ion/molecule reactions, ethylchloride, methylamine, ethylamine, propylamines, butylamines

scholarly journals On apparent barrier-free reactions

2020 ◽  
Vol 3 (1) ◽  
pp. 3-8
Author(s):  
Maikel Ballester
Keyword(s):  
Low Temperature ◽  
Chemical Reactions ◽  
Rate Constant ◽  
Kinetic Models ◽  
Rate Coefficient ◽  
Minimum Energy ◽  
Temperature Limit ◽  
Rate Coefficients ◽  
Minimum Energy Path ◽  
Full Dimension

Rate coefficients of bi-molecular chemical reactions are fundamental for kinetic models. The rate coefficient dependence on temperature is commonly extracted from the analyses of the reaction minimum energy path. However, a full dimension study of the same reaction may suggest a different asymptotic low-temperature limit in the rate constant than the obtained from the energetic profile.

scholarly journals The Formation of Interstellar Molecules via Radiative Association Reactions

1980 ◽  
Vol 87 ◽  
pp. 323-324
Author(s):  
David Smith ◽  
Nigel G. Adams
Keyword(s):  
Rate Coefficients ◽  
Rate Data ◽  
Association Rate ◽  
Interstellar Molecules ◽  
Ion Molecule Reactions ◽  
Radiative Association ◽  
Temperature Dependences ◽  
Association Reaction

The radiative association rate coefficients and their temperature dependences have been estimated for several likely interstellar ion-molecule reactions from laboratory collisional association rate data. They include the CH3+ + H2 and CH3+ + H2O reactions, which we suggest lead to CH4 and CH3OH respectively, and the critical association reaction C+ + H2.

Barrierless Reactions of Three Benzonitrile Radical Cations with Ethylene

2020 ◽  
Vol 73 (8) ◽  
pp. 705
Author(s):  
Oisin J. Shiels ◽  
P. D. Kelly ◽  
Stephen J. Blanksby ◽  
Gabriel da Silva ◽  
Adam J. Trevitt
Keyword(s):  
Ion Trap ◽  
Radical Cations ◽  
Branching Ratios ◽  
Ring Closure ◽  
Van Der Waals Complexes ◽  
Rate Coefficients ◽  
Ion Trap Mass Spectrometry ◽  
Closure Mechanism ◽  
Product Ions ◽  
Product Branching

Reactions of three protonated benzonitrile radical cations with ethylene are investigated. Product branching ratios and reaction kinetics, measured using ion-trap mass spectrometry, are reported and mechanisms are developed with support from quantum chemical calculations. Reactions proceed via pre-reactive van der Waals complexes with no energy barrier (above the reactant energy) and form radical addition and addition–elimination product ions. Rate coefficients are 4-dehydrobenzonitrilium: 1.72±0.01×10−11 cm3 molecule−1 s−1, 3-dehydrobenzonitrilium: 1.85±0.01×10−11 cm3 molecule−1 s−1, and 2-dehydrobenzonitrilium: 5.96±0.06×10−11 cm3 molecule−1 s−1 (with±50% absolute uncertainty). A ring-closure mechanism involving the protonated nitrile substituent is proposed for the 2-dehydrobenzonitrilium case and suggests favourable formation of the protonated indenimine cation.

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