scholarly journals Metastable ion studies. VI. The identification of C2H5N+• ion structures from their characteristic kinetic energy releases

1976 ◽  
Vol 54 (7) ◽  
pp. 1007-1014 ◽  
Author(s):  
John L. Holmes ◽  
Johan K. Terlouw
Keyword(s):  
Kinetic Energy ◽  
Energy Release ◽  
Kinetic Energy Release ◽  
Open Chain ◽  
Structural Identity ◽  
Free Region ◽  
Unequivocal Identification ◽  
Field Free Region ◽  
Labelling Experiment ◽  
Precursor Molecules

Metastable peaks for the fragmentation C2H5N+• → C2H4N+ + H• have been studied in the first field-free region of a double focussing mass spectrometer. Isomeric structures of C2H5N+• ions derived from a variety of precursor molecules were characterised by their metastable peak shape and kinetic energy release. The identifications were aided by appropriate deuterium labelling experiments. Four isomeric ionsr [Formula: see text]were shown to retain their structural identity within the ion energy and lifetime ranges observable in these experiments. Ion (a), generated from aziridine was found to be indistinguishable from its open chain isomer [Formula: see text]The results closely parallel those previously found for the isoelectronic C2H5N+• ions, but the differences in characteristic kinetic energy release are smaller. A simple deuterium exchange labelling experiment may be necessary for the unequivocal identification of C2H5N+• ion structures.

Metastable Ion Studies. V. The Identification of C2H4O+ · Ion Structures from their Characteristic Kinetic Energy Releases

1975 ◽  
Vol 53 (14) ◽  
pp. 2076-2083 ◽  
Author(s):  
John L. Holmes ◽  
Johan K. Terlouw
Keyword(s):  
Kinetic Energy ◽  
Kinetic Energy Release ◽  
Ethyl Vinyl Ether ◽  
Ethyl Vinyl ◽  
Free Region ◽  
Unequivocal Identification ◽  
Field Free Region ◽  
Activation Data ◽  
Labelling Experiment ◽  
Good Energy

Metastable ion peaks for the fragmentation C2H4O+ • → C2H3O+ + H• have been studied in the first field-free region of a double focussing mass spectrometer under conditions of good energy resolution. Three isomeric C2H4O+ • ions were generated[Formula: see text] (b) CH3CHO+, and (c) CH2=CHOH+ • from ethylene oxide, acetaldehyde, and ethyl vinyl ether respectively, each fragment producing a different 1m* peak having a characteristic shape and kinetic energy release. The above ions do not therefore interconvert prior to fragmentation and their characteristic 1m* peaks permit their unequivocal identification, thus providing a powerful method for ion structure determination.In agreement with some recent collisional activation data it was found that the unbranched aldehydes, cyclic alcohols, and 2-haloethanols investigated generated (c) type C2H4O+ • ions. These are also produced by glycidol and α-furfuryl alcohol. Some compounds generated composite 1m* peaks, e.g. 1,3-dioxolane produces (a) and (c) ions, while compounds which produce prominent C2H5O+ ions having the protonated acetaldehyde structure, generate m/e 44 ions of structures (b) and (c). In isopropanol these components were separated by a deuterium labelling experiment. Contrary to earlier proposals, pyruvic acid does not generate (b) type ions but produces predominantly ions of structure (c).

scholarly journals Kinetic Energy Release in Metastable Transitions. I

1967 ◽  
Vol 22 (1) ◽  
pp. 15-19 ◽  
Author(s):  
M. Barber ◽  
K. R. Jennings ◽  
R. Rhodes
Keyword(s):  
Kinetic Energy ◽  
Energy Release ◽  
Mass Spectrometer ◽  
Kinetic Energy Release ◽  
Peak Shape ◽  
Free Region ◽  
Field Free Region ◽  
Product Ions ◽  
Electrostatic Analyser

A method is described for detecting metastable transitions which take place with the release of kinetic energy in the field-free region between the source and electrostatic analyser of a doublefocusing mass spectrometer, and a procedure is given for evaluating the kinetic energy release. Values are given for a number of transitions and are in agreement with those obtained by other methods where comparison is possible. The variation of peak shape with accelerating voltage is ascribed to the varying efficiency with which product ions are collected.

Isotope effects on kinetic energy release. Elimination of CH4 from [CH3CHOH]+ and [CH2OCH3]+

1989 ◽  
Vol 93 (2) ◽  
pp. 215-223 ◽  
Author(s):  
Kevin F. Donchi ◽  
Einar Uggerud ◽  
Georg Hvistendahl ◽  
Peter J. Derrick
Keyword(s):  
Kinetic Energy ◽  
Energy Release ◽  
Isotope Effects ◽  
Kinetic Energy Release

scholarly journals Toward fully quantum modelling of ultrafast photodissociation imaging experiments. Treating tunnelling in the ab initio multiple cloning approach

2016 ◽  
Vol 194 ◽  
pp. 81-94 ◽  
Author(s):  
Dmitry V. Makhov ◽  
Todd J. Martinez ◽  
Dmitrii V. Shalashilin
Keyword(s):  
Kinetic Energy ◽  
Ab Initio ◽  
Energy Release ◽  
Kinetic Energy Release ◽  
Total Kinetic Energy ◽  
Recent Effort ◽  
Experimental Measurements ◽  
Quantum Level ◽  
Hydrogen Atoms ◽  
Quantum Simulations

We present an account of our recent effort to improve simulation of the photodissociation of small heteroaromatic molecules using the Ab Initio Multiple Cloning (AIMC) algorithm. The ultimate goal is to create a quantitative and converged technique for fully quantum simulations which treats both electrons and nuclei on a fully quantum level. We calculate and analyse the total kinetic energy release (TKER) spectra and Velocity Map Images (VMI), and compare the results directly with experimental measurements. In this work, we perform new extensive calculations using an improved AIMC algorithm that now takes into account the tunnelling of hydrogen atoms. This can play an extremely important role in photodissociation dynamics.

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