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.

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%).

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

1968 ◽  
Vol 46 (12) ◽  
pp. 2141-2146 ◽  
Author(s):  
Howard Pritchard ◽  
J. C. J. Thynne ◽  
A. G. Harrison
Keyword(s):  
Rate Constants ◽  
Methyl Formate ◽  
Ion Molecule Reactions ◽  
Dipole Interactions ◽  
Induced Dipole ◽  
Energy Formula ◽  
Good Agreement

The following ion–molecules reactions have been found to occur in DCOOH for ions produced by bombardment with electrons of 10–15 eV energy (all rate constants in cm3 molecule−1 units).[Formula: see text]In methyl formate the following reactions have been identified and rate constants measured for ions formed by bombardment with electrons of 10–15 eV energy.[Formula: see text]Experiments using DCO2CH3 show that reaction [f] involves transfer of the methyl hydrogen at a rate 1.5 times that of the formyl hydrogen while reaction [g] involves transfer from only the methyl position of CH3OH+. The rate constants for all reactions are considerably higher than predicted on the basis of ion–induced dipole interactions only but are in good agreement with values calculated by including 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>

Ion-molecule reactions in acetone-water mixtures

1966 ◽  
Vol 19 (1) ◽  
pp. 59 ◽  
Author(s):  
Souza BC de ◽  
JH Green
Keyword(s):  
Hydrogen Atom ◽  
Proton Transfer ◽  
Transfer Process ◽  
Hydrogen Atom Transfer ◽  
Mass Spectrometric ◽  
Transfer Mechanism ◽  
Atom Transfer ◽  
Ion Molecule Reactions ◽  
Acetone Water

Mass-spectrometric studies of ion-molecule reactions in acetone-water mixtures at 70 eV and 20 eV electron energies are described. The results provide evidence in favour of the proton transfer mechanism rather than for a hydrogen atom transfer process for the production of M + 1 ions.

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.

Bimolecular reactions of nucleophiles in the gas phase. The reaction of the methoxide anion with ketones. An ion cyclotron resonance study

1980 ◽  
Vol 33 (10) ◽  
pp. 2271 ◽  
Author(s):  
G Klass ◽  
JH Bowie
Keyword(s):  
Gas Phase ◽  
Cyclotron Resonance ◽  
Ion Cyclotron Resonance ◽  
Bimolecular Reactions ◽  
Methyl Nitrite ◽  
Ion Molecule Reactions ◽  
Ion Cyclotron ◽  
Methoxide Anion

The methoxide anion (produced from methyl nitrite) reacts with neutral ketones (M) to form non-decomposing(M-H+)- ions. The (M-H+)- ions are ambident species and they undergo a number of ion-molecule reactions, including (i) characteristic reactions through the carbanion centre with methyl nitrite, and (ii) for acetone, the formation of an [M +(M- H+)]- ion. In several cases peaks due to collision-stabilized (M+MeO-) ions are observed (e.g. MeO-/acetone), but they are not detected for the majority of cases studied.

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