ChemInform Abstract: Product Kinetic Energy Release Distributions as a Probe of the Energetics and Mechanisms of Organometallic Reactions Involving the Formation of Metallacyclobutanes in the Gas Phase.

ChemInform ◽  
1989 ◽  
Vol 20 (25) ◽  
Author(s):  
P. A. M. VAN KOPPEN ◽  
D. B. JACOBSON ◽  
A. ILLIES ◽  
M. T. BOWERS ◽  
M. HANRATTY ◽  
...  
1989 ◽  
Vol 111 (6) ◽  
pp. 1991-2001 ◽  
Author(s):  
Petra A. M. Van Koppen ◽  
Denley B. Jacobson ◽  
Andreas Illies ◽  
Michael T. Bowers ◽  
Maureen Hanratty ◽  
...  

2017 ◽  
Vol 23 (6) ◽  
pp. 319-326 ◽  
Author(s):  
AW Colburn ◽  
Peter J Derrick ◽  
Richard D Bowen

The value of the Grand Scale ‘Magnificent Mass Machine’ mass spectrometer in investigating the reactivity of ions in the gas phase is illustrated by a brief analysis of previously unpublished work on metastable ionised n-pentyl methyl ether, which loses predominantly methanol and an ethyl radical, with very minor contributions for elimination of ethane and water. Expulsion of an ethyl radical is interpreted in terms of isomerisation to ionised 3-pentyl methyl ether, via distonic ions and, possibly, an ion-neutral complex comprising ionised ethylcyclopropane and methanol. This explanation is consistent with the closely similar behaviour of the labelled analogues, C3H7CH2CD2OCH3+. and C3H7CD2CH2OCH3+., and is supported by the greater kinetic energy release associated with loss of ethane from ionised n-propyl methyl ether compared to that starting from directly generated ionised 3-pentyl methyl ether.


1979 ◽  
Vol 57 (21) ◽  
pp. 2827-2833 ◽  
Author(s):  
Nora E. Middlemiss ◽  
Alex. G. Harrison

Gaseous protonated acids fragment in the first drift region of a double focussing mass spectrometer to yield the corresponding acylium ion and water. The metastable peaks for this fragmentation reaction have been recorded for the protonated acids from acetic to valeric and the kinetic energy release distributions evaluated from the metastable peak shapes. The protonated acids were produced by dissociative ionization of the ethyl, propyl, and butyl esters. The results provide evidence for two structures for gaseous protonated acids. Fragmentation of the hydroxyl protonated structure, a minor contributor to the metastable peak intensity, shows a low kinetic energy release (T(most probable) = 0.02 eV) as would be expected for a simple bond fission reaction. Fragmentation of the carbonyl protonated acid, which represents the major part of the metastable peak, is accompanied by a muchlarger kinetic energy release (T(most probable) = 0.30 to 0.43 eV). This result is interpreted in terms of an activation barrier for fragmentation of the carbonyl protonated acid which is considerably greater than the reaction endothermicity, with the excess energy being partitioned between internal energy and kinetic energy of the fragments. The results indicate that the addition of the acylium ion to water in the gas phase to produce the carbonyl protonated acid has an activation energy barrier.


Author(s):  
Kevin F. Donchi ◽  
Einar Uggerud ◽  
Georg Hvistendahl ◽  
Peter J. Derrick

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