ION–MOLECULE REACTIONS IN METHYL ALCOHOL AND METHYL-d3 ALCOHOL

1966 ◽  
Vol 44 (14) ◽  
pp. 1655-1661 ◽  
Author(s):  
J. C. J. Thynne ◽  
F. K. Amenu-Kpodo ◽  
A. G. Harrison

The rate constants for the hydrogen-transfer ion-molecule reactions[Formula: see text]have been measured at thermal ion energies and found to be 12 × 10−10 cm3 molecule−1 s−1 and 8.0 × 10−10 cm3 molecule−1 s−1 respectively. The rate coefficients at higher ion energies (3.7 eV ion exit energy) show little change from these values. Reactions [a] and [b] have also been studied using CD3OH and it is found that in reaction [a] the hydroxyl hydrogen is transferred 2.5 times more readily at low ion energies and 1.8 times more readily at high ion energies than a methyl hydrogen. This rather small specificity would appear to preclude formation of a "locked-in" collision complex even at low ion energies.


1967 ◽  
Vol 45 (12) ◽  
pp. 1321-1327 ◽  
Author(s):  
A. G. Harrison ◽  
J. C. J. Thynne

The concurrent ion–molecule reactions in mixtures of HCl and HCN with D2 and CD4 have been studied by the ratio plot method. The following reactions have been detected in mixtures with HCN and their cross sections determined at 10.5 V cm−1 repeller field strength. [Formula: see text]In mixtures of D2 and CD4 with HCl the following reactions have been detected and cross sections determined. [Formula: see text]Rate constants for the self-reactions in HCN and HCl have been measured both at 10.5 V cm1 repeller field and at thermal ion energies.



1971 ◽  
Vol 49 (13) ◽  
pp. 2217-2222 ◽  
Author(s):  
A. A. Herod ◽  
A. G. Harrison ◽  
N. A. McAskill

The reactions of the molecular ion have been studied as a function of the ion kinetic energy for methyl fluoride and methyl chloride. The following reactions are observed[Formula: see text]For methyl fluoride (X = F) reactions c and d have kinetic energy thresholds and become significant at high ion energies. For CH3Cl (X = Cl) reaction a is not observed and reactions c and d are of only minor importance at high ion energies. Rate coefficients for the molecular ions and a number of fragment ions as well as rate coefficients for further reaction of CH4X+ are reported.



1966 ◽  
Vol 44 (12) ◽  
pp. 1351-1359 ◽  
Author(s):  
A. G. Harrison ◽  
A. Ivko ◽  
T. W. Shannon

The rate constants for the ion–molecule reactions forming the protonated molecule in CH3CN, H2, CH4, and CH3OCH3, the equivalent reactions in the deuteriated species, and the reactions forming COD+ in CO–CD4 mixtures have been measured at thermal energies and at 10.5 V/cm repeller field strength. For H2, HD, D2 and the reactions in CO–CD4 mixtures the rate constant for the thermal reaction is approximately 0.3–0.5 that of the 10.5 V/cm rate constant. For all other cases the ratio of rate constants is approximately unity as predicted by the ion-induced dipole model. The absolute values of the rate constants in most cases are considerably lower than predicted by theory.



1967 ◽  
Vol 45 (24) ◽  
pp. 3119-3128 ◽  
Author(s):  
E. G. Jones ◽  
A. G. Harrison

The ion–molecule reactions in gaseous methyl amine have been studied. The following reactions have been identified and their rate coefficients (all in cm3 molecule−1 s−1 units) determined for ions of 3.4 eV ion exit energy. [Formula: see text]Reactions [a] and [c] were also studied at thermal ion energies and little variation of the rate coefficients with ion energy was found in contrast with theoretical predictions.



1967 ◽  
Vol 45 (24) ◽  
pp. 3107-3117 ◽  
Author(s):  
S. K. Gupta ◽  
E. G. Jones ◽  
A. G. Harrison ◽  
J. J. Myher

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.



2020 ◽  
Author(s):  
Oisin Shiels ◽  
P. D. Kelly ◽  
Cameron C. Bright ◽  
Berwyck L. J. Poad ◽  
Stephen Blanksby ◽  
...  

<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>



1991 ◽  
Vol 69 (2) ◽  
pp. 363-367
Author(s):  
Guoying Xu ◽  
Jan A. Herman

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



1980 ◽  
Vol 87 ◽  
pp. 323-324
Author(s):  
David Smith ◽  
Nigel G. Adams

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.



1976 ◽  
Vol 31 (5) ◽  
pp. 414-421 ◽  
Author(s):  
Karl-Peter Wanczek

Abstract The mass spectrum of tetramethyldiphosphine and the ion chemistries of this compound and of its mixtures with phosphine and dimethylphosphine have been investigated by ion cyclotron resonance spectrometry. Numerous ion molecule reactions have been observed. The rate constants of the two most abundant ions formed by the molecular ion, the tetramethyldiphosphonium ion, H(CH3)2P-P(CH3)2+ and the hexamethyltriphosphonium ion, P3(CH3)6+ , are k2.35≦0.1X10-10 cm3 molecule-1 s-1 and k2.40 = 1.5 X10-10 cm3 molecule -1 s -1 respectively. The structures of several ions have been determined with the aid of their ion-molecule reactions. The ions m/e = 79 and 93 are thought to have the structures HP - P(CH3)H+ and HP-P(CH3)2+ . The most probable structures of the ions m/e = 169 and 183 are HP(CH3)2-P(CH3)-P(CH3)2+ and (CH3)2P-P(CH3) - P(CH3)3+ . The protonated molecule undergoes several ion-molecule reactions, which proceed via an intermediate, m/e = 183, [(CH3)6P3+]* which is detected by double resonance experiments.



2010 ◽  
Vol 36 (5) ◽  
pp. 411-416 ◽  
Author(s):  
C. van der Linde ◽  
R. F. Höckendorf ◽  
O. P. Balaj ◽  
M. K. Beyer


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