The need for adequate thermochemical data for the interpretation of fragmentation mechanisms and ion structure assignments

Abstract The behavior of the even‐electron mass 150 ions, (presumably nitrobenzoyl cations) generated by simple α‐cleavage of m ‐ and p ‐nitrobenzoic acid derivatives, undergo two competing secondary fragmentations to yield odd‐electron ions by the expulsion of NO and NO 2 . Expulsion of NO from the mass 150 ions from p ‐nitro compounds is far greater than expulsion of NO from those generated from m ‐nitro compounds. In addition, the behavior of the even‐electron mass 136 ions, generated from m ‐ and p ‐nitrobenzyl compounds, was compared to that of the mass 150 ions and they were found to decompose in a similar fashion. From our results we conclude that the decomposing mass 136 ions produced from either the m ‐ or p ‐nitrobenzyl compounds, or both, do not have the nitropylium structure; our data are more consistent with the decomposing ions having nitrobenzyl structures.

Fragmentation

Cleavage (geology)

10.1002/oms.1210020507

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Citations (24)

Fragmentation of 2,5-diketopiperazine cyclic dipeptide ions

Журнал технической физики (2022)

A. A. Basalaev В. В. Кузьмичев M. N. Panov Aleksey V. Petrov О. В. Смирнов

The mechanism of radiation damage to 2,5-diketopiperazine (DKP, C 4 H 6 N 2 O 2 ) molecules in the gas phase upon interaction with He 2+ ions with an energy Ep = 4 keV/u has been investigated. The relative cross sections of various elementary processes occurring in single collisions of DKP with ions have been measured for the first time. The channels of fragmentation processes of singly charged ions have been studied experimentally. The DFT method was used to calculate the geometry of molecules and singly charged DKP ions, as well as the energies of the main experimentally observed channels of fragmentation of these ions. Keywords: electron capture, dipeptides, molecular ion fragmentation.

Fragmentation

10.21883/tp.2022.07.54477.309-21

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Citations (2)

Further correlations between fragment ion intensity and critical energy. Unimolecular covalent bond fragmentation

Organic Mass Spectrometry (1985)

Maurice M. Bursey Donald J. Harvan J. Ronald Hass Ernest I. Becker Byron H. Arison

Abstract A correlation of fragment ion intensity with critical energy found in the collisional activation spectra of [C 4 Ph] + ˙ ions produced by electron impact can also be found in the unimolecular mass‐analysed ion kinetic energy spectra of these ions. The P(E) functions of the unimolecular and collisionally activated ions should differ not only in width but also in structure and therefore, the hypothesis that P(E) functions do not have an important effect on these correlations is tested successfully.

Fragmentation

Fragment (logic)

Intensity

10.1002/oms.1210200305

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Citations (8)

Negative ions as a probe to study the fragmentation of clusters and small molecular targets as a function of the excitation energy

Journal of Physics Conference Series (2009)

R. Brédy J. Bernard Li Chen Bin Li X. Ma

The production rate of negative ions in collisions between neutral, singly and multiply charged ions with clusters or small molecules is a crucial parameter to study the fragmentation of the targets as a function of the excitation energy (CIDEC method). We report on high production yields of negative ions in collisions between Fq+(q = 1-3) ions and fullerene C60 and adenine molecules. The dynamics of the formation of the negative ion in such collisions is discussed.

Fragmentation

Excitation function

10.1088/1742-6596/194/10/102001

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Mass spectra of the negative ions of some dioxanes

Russian Chemical Bulletin (1999)

И. И. Фурлей V. S. Shmakov D. L. RAKHMANKULOV S. S. ZLOTSKII

Fragmentation

10.1007/bf02494872

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Citations (1)