Kinetic Energy Release and Metastable Transitions II. The Decomposition of Doubly-Charged Ions of Aliphatic and Alicyclic Hydrocarbons

1969 ◽  
Vol 24 (1) ◽  
pp. 134-138
Author(s):  
M. Barber ◽  
K. R . Jennings
Keyword(s):  
Kinetic Energy ◽  
Energy Release ◽  
Kinetic Energy Release ◽  
Doubly Charged Ions ◽  
Fragment Ions ◽  
Degree Of Unsaturation ◽  
High Kinetic Energy ◽  
Double Focusing ◽  
Doubly Charged ◽  
Charged Ions

AbstractThe decompositions of doubly-charged ions given by a number of C3 -C8 aliphatic and alicyclic hydrocarbons have been investigated in a double-focusing mass spectrometer. Many processes were found in which high kinetic energy CH3+ and C2H3+ ions are formed. Doubly-charged ions fragment by more than one route and in many cases, high kinetic energy fragment ions are formed in at least two different ways. Metastable transitions common to several compounds were observed, the intensities rising as the degree of unsaturation increased.

A method for calculating the shapes of peaks resulting from fragmentations of metastable ions in a mass spectrometer. II. Peak shapes arising from a distribution of kinetic energy releases: determination of distribution function

1980 ◽  
Vol 373 (1752) ◽  
pp. 13-25 ◽  
Keyword(s):  
Kinetic Energy ◽  
Energy Release ◽  
Preceding Paper ◽  
Kinetic Energy Release ◽  
Peak Shape ◽  
Doubly Charged Ions ◽  
Metastable Ions ◽  
Product Ions ◽  
Doubly Charged

Following the calculations described in the preceding paper (part I), which determine the MIKE peak shape arising from a discrete kinetic energy release, a method is presented for extending the calculations for the determination of the kinetic energy release distribution, n (T), from any experimental peak shape. This new approach has the advantage, compared to previous work, that the distribution can be obtained directly and does not involve any trial and error methods. It applies equally well where discrimination occurs against some of the product ions having components of velocity parallel to the length of the instrument slits. A variety of peak shapes have been investigated and several examples are given of the energy release distribution for various ionic reactions. Charge separation reactions of doubly-charged ions have been examined and in one case, the reaction 91 2+ -> 52 + in toluene, the energy release function exhibits fine structure, which has not previously been observed.

scholarly journals Die kinetische Energie ionisierter Molekülfragmente

1966 ◽  
Vol 21 (12) ◽  
pp. 2069-2082
Author(s):  
R. Fuchs
Keyword(s):  
Initial Energy ◽  
Energy Spectra ◽  
Charged Fragment ◽  
Doubly Charged Ions ◽  
Fragment Ions ◽  
High Kinetic Energy ◽  
New Type ◽  
Singly Charged ◽  
Doubly Charged ◽  
Charged Ions

It is well known that in the initial energy spectra of hydrocarbon fragment ions formed by electron impact, satellite ion groups occur which are believed to be mainly due to the fragmentation of doubly charged ions into two singly charged fragments. By using an electron energy of 150 eV a new type of satellite was observed in the initial energy spectra of C1Hk+ and C2Hl+ fragment ions from hydrocarbons with three and more carbon atoms. The n-paraffins were investigated systematically up to n-decane. Because the initial energy of these satellites is nearly twice the initial energy of the already well known “first” satellites, it is suggested that these newly discovered “second” satellites are due to an analogous fragmentation process of the typeA+++→B+ + C++.Therefore, a careful search was made for the corresponding doubly charged fragment ions of high kinetic energy. Well pronounced satellite groups of doubly charged fragment ions were, indeed, found. Their momentum approximately equals the momentum of the corresponding “second” satellites of singly charged fragments, which supports the suggested mechanism.

Kinetic Energy Release Distributions in the Fragmentation of O2 Molecules Induced by Fast Highly Charged Ions

2001 ◽  
Vol T92 (1) ◽  
pp. 244-247
Author(s):  
U. Werner ◽  
B. SiegTmann ◽  
R. Mann ◽  
N. M. Kabachnik ◽  
H. O. Lutz
Keyword(s):  
Kinetic Energy ◽  
Energy Release ◽  
Kinetic Energy Release ◽  
Highly Charged Ions ◽  
Charged Ions

scholarly journals Photodissociation Dynamics of Arn+ Cluster Ions

1994 ◽  
Vol 14 (1-3) ◽  
pp. 15-29 ◽  
Author(s):  
Takashi Nagata
Keyword(s):  
Kinetic Energy ◽  
Energy Release ◽  
Simulation Analysis ◽  
Kinetic Energy Release ◽  
Cluster Ions ◽  
Angular Distributions ◽  
High Kinetic Energy ◽  
Spectral Profiles ◽  
Direct Dissociation ◽  
Energy And Angular Distributions

The time-of-flight (TOF) spectra of Ar+ and Ar fragments produced in the photodissociation of Arn+ (3 ≦ n ≧ 24) were measured at wavelength around 540 nm. The kinetic-energy and angular distributions of the neutral photofragments were obtained for n = 3, 9 and 24 by a simulation analysis of the measured TOF spectral profiles. The overall aspect of the photodissociation process of Arn+ is deduced from these distributions within the context of trimer ion core model; a linear Ar3+ core is solvated by neutral Ar atoms. For Arn+ with 4 ≦ n ≲ 14, direct dissociation of the Ar3+ chromophoric core gives rise to Ar+ and/or Ar fragments with a high kinetic energy release. For the larger Arn+ (n ≳ 14), the production of high-kinetic-energy fragments is suppressed; “evaporation” of the solvent Ar atoms is instead the dominant channel of photofragmentation.

The mass and ion kinetic energy spectra of H 2 , HD and D 2

1972 ◽  
Vol 327 (1568) ◽  
pp. 1-11 ◽  
Keyword(s):  
Fine Structure ◽  
Kinetic Energy ◽  
Energy Release ◽  
Isotope Effects ◽  
Kinetic Energy Release ◽  
Energy Spectra ◽  
Vibrational States ◽  
First Excited State ◽  
Ion Kinetic Energy ◽  
Double Focusing

The collision-induced reactions, (1) H +· 2 → H + + H · , (2) H + 3 → H + + H 2 , and (3) H + 3 → H +· 2 + H · , and the corresponding reactions of the deuterated species, have been examined for their kinetic energy release using a double focusing mass spectrometer. Reaction (1) encompasses two discrete processes, the first apparently involving only the ground electronic state of H + 2 and the second apparently occurring via excitation to the repulsive first excited state. Isotope effects on the kinetic energy release associated with the transition to the repulsive state in process (1) are consistent with the proposed mechanism. Process (2) gives a ‘meta- ­ stable peak’ which shows fine structure, possibly due to individual vibrational states of H 2 . Reaction (3) occurs by electronic transition to a repulsive state(s).

Charge stripping and delayed autoionization in doubly charged ions of the noble gases

1985 ◽  
Vol 402 (1823) ◽  
pp. 373-400 ◽  
Keyword(s):  
Black Body ◽  
Black Body Radiation ◽  
Translational Energy ◽  
Rare Gases ◽  
Doubly Charged Ions ◽  
Free Process ◽  
Singly Charged ◽  
Double Focusing ◽  
Doubly Charged ◽  
Charged Ions

Doubly charged ions of each of the rare gases neon, argon, krypton and xenon, formed by electron impact and accelerated through 6 kV in a double-focusing mass spectrometer, are ionized to the corresponding triply charged ions via processes of at least two general kinds. The first proceeds under collision-free conditions, and can be attributed to delayed (microsecond) autoionization. An alternative explanation involving transitions from high Rydberg states, induced by the 350 K black-body radiation within the analyser vacuum housing, cannot be entirely ruled out. Other ionization processes require a collision with a molecule of collision gas, and result in a measurable loss of translational energy. In this paper the knowledge of analogous processes of the corresponding singly charged ions is reviewed, the general features of the translational energy spectra are established, and effort is devoted to the characterization of the collision-free process. The collision-induced processes have been interpreted in terms of known metastable states of the doubly charged ions.

scholarly journals Identification and Study of Biomarkers from Novichok-Inhibited Butyrylcholinesterase in Human Plasma

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3810
Author(s):  
Woo-Hyeon Jeong ◽  
Jin-Young Lee ◽  
Kyoung-Chan Lim ◽  
Hyun-Suk Kim
Keyword(s):  
Enzyme Activity ◽  
Human Plasma ◽  
Active Site ◽  
Trace Analysis ◽  
Nerve Agents ◽  
Doubly Charged Ions ◽  
Fragment Ions ◽  
Doubly Charged ◽  
Charged Ions

To identify biomarkers of ethyl (1-(diethylamino)ethylidene)phosphoramidofluoridate (A234)- or methyl (1-(diethylamino)ethylidene)phosphoramidofluoridate (A232)-inhibited butyrylcholinesterase (BChE), we investigated nonapeptide adducts containing the active site serine, which plays a key role in enzyme activity, using LC-MS/HRMS. Biomarkers were acquired as expected, and they exhibited a significant amount of fragment ions from the inhibiting agent itself, in contrast to the MS2 spectra of conventional nerve agents. These biomarkers had a higher abundance of [M+2H]2+ ions than [M+H]+ ions, making doubly charged ions more suitable for trace analysis.

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