CH5N2 hydrazyl radicals, cations and dication radicals studied by mass spectrometry. Is the N-protonated formaldehyde hydrazon cation +CH2NHNH2 a bridged species?

Burgers, Peter C.; Drewello, Thomas; Schwarz, Helmut; Terlouw, Johan K.

doi:10.1016/0168-1176(89)83038-1

Cited by 11 publications

(21 citation statements)

References 33 publications

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“…The value reported by Dibeler et al 20 (9.7 ( 0.2 eV) is in accord with our AE of 9.65 ( 0.05 eV. However, Akopyan and Vilesov 21 and Burgers et al 14 give values which are more than 1 eV lower. Akopyan and Vilesov 21 have also reported an AE of 11.2 ( 0.2 eV for another possible structure of m/z 45, (CH 3 ) 2 NH + .…”

Section: Resultssupporting

confidence: 94%

Entropy Effects in the Fragmentation of 1,1-Dimethylhydrazine Ions

et al. 2007

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The 1,1-dimethylhydrazine ion ((CH3)2NNH2+*) has two low-energy dissociation channels, the loss of a hydrogen atom to form the fragment ion m/z 59, (CH3)(CH2)NNH2+, and the loss of a methyl radical to form the fragment ion m/z 45, the methylhydrazyl cation, CH3NNH2+. The dissociation of the 1,1-dimethylhydrazine ion has been investigated using threshold photoelectron-photoion coincidence (TPEPICO) spectroscopy, in the photon energy range 8.25-31 eV, and tandem mass spectrometry. Theoretical breakdown curves have been obtained from a variational transition state theory (VTST) modeling of the two reaction channels and compared to those obtained from experiment. Seven transition states have been found at the B3-LYP/6-31+G(d) level of theory for the methyl radical loss channel in the internal energy range of 2.32-3.56 eV. The methyl loss channel transition states are found at R(N-C) = 4.265, 4.065, 3.965, 3.165, 2.765, 2.665, and 2.565 A over this internal energy range. Three transition states have been found for the hydrogen atom loss channel: R(H-C) = 2.298, 2.198, and 2.098 A. The DeltaS++(45) value, at an internal energy of 2.32 eV and a bond distance of R(N-C) = 4.265 A, is 65 J K-1 mol-1. As the internal energy increases to 3.56 eV the variational transition state moves to lower R value so that at R(N-C) = 2.565 A, the DeltaS++ decreases to 29 J K-1 mol-1. For the hydrogen atom loss channel the variation in DeltaS++ is less than that for the methyl loss channel. To obtain agreement with the experimental breakdown curves, DeltaS++(59) = 26-16 J K-1 mol-1 over the studied internal energy range. The 0 K enthalpies of formation (DeltafH0) for the two fragment ions m/z 45 and m/z 59 have been calculated from the 0 K activation energies (E0) obtained from the fitting procedure: DeltafH0[CH3NNH2+] = 906 +/- 6 kJ mol-1 and DeltafH0[(CH3)(CH2)NNH2+] = 822 +/- 7 kJ mol-1. The calculated G3 values are DeltafH0[CH3NNH2+] = 911 kJ mol-1 and DeltafH0[(CH3)(CH2)NNH2+] = 825 kJ mol-1. In addition to the two low-energy dissociation products, 21 other fragment ions have been observed in the dissociation of the 1,1-dimethylhydrazine ion as the photon energy was increased. Their appearance energies are reported.

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Section: Resultssupporting

confidence: 94%

Entropy Effects in the Fragmentation of 1,1-Dimethylhydrazine Ions

et al. 2007

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“…[51][52][53][54]65,[67][68][69][70][71][72][73] Electron transfer, both dissociative and nondissociative, usually dominates the product ion yield in such encounters. When the electron is transferred from the neutral to the dication, a pair of monocations is formed.…”

Section: Introductionmentioning

confidence: 99%

The formation of NO+ from the reaction of N22+ with O2

Ricketts

Harper

et al. 2005

The Journal of Chemical Physics

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Guided-ion beam study of the O 2 + +C 2 H 2 charge-transfer and chemical reaction channels J. Chem. Phys. 110, 4291 (1999) We have studied the potentially ionospherically significant reaction between N 2 2+ with O 2 using position-sensitive coincidence spectroscopy. We observe both nondissociative and dissociative electron transfer reactions as well as two channels involving the formation of NO + . The NO + product is formed together with either N + and O in one bond-forming channel or O + and N in the other bond-forming channel. Using the scattering diagrams derived from the coincidence data, it seems clear that both bond-forming reactions proceed via a collision complex ͓N 2 O 2 ͔ 2+ . This collision complex then decays by loss of a neutral atom to form a daughter dication ͑NO 2 2+ or N 2 O 2+ ͒, which then decays by charge separation to yield the observed products.

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“…113 In the last two decades, ECID has been applied for the characterization of the structures of doubly charged precursor ions, 107,116,117 differentiation of isomers 112,118 and the determination of fragmentation pathways. 114,119 It is possible to use ECID as an alternative to charge stripping for the determination of the ionization energies of singly charged ions. It has an advantage over charge stripping in that with a low-IE target, the electron-capture cross-section is higher.…”

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confidence: 99%

Charge permutation reactions in tandem mass spectrometry

McLuckey

2004

J. Mass Spectrom.

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Central to the tandem mass spectrometry experiment is the process that gives rise to product ions, i.e. the reaction intermediate to stages of mass analysis. Changes in mass or charge of the parent ion (or both) are generally readily detected by all forms of tandem mass spectrometry. Charge changing, or charge permutation, reactions have a long history in mass spectrometry. However, with the advent of new ionization methods, such as electrospray ionization, and the expansion of tandem mass spectrometry instrumentation to include ion trapping instruments, the past decade has seen a major increase in the types of charge permutation reactions that can be studied. Most charge permutation reactions involve electrons or protons as the charge mediating agents. This report, therefore, provides an overview of charge permutation reactions involving protons or electrons. Particular emphasis is placed on processes that involve interactions of precursor ions with gaseous neutral species, electrons or oppositely charged ions. Charge permutation reactions involving electron gain/loss are described first according to a rough order of the energy required for the reaction beginning with the most endoergic reactions and ending with the most exoergic reactions. An analogous approach is then taken with charge permutation reactions involving proton gain/loss. Important charge permutation reactions discussed herein, among others, include those referred to as charge inversion, charge stripping, electron capture dissociation, collision-induced ionization and charge separation. These reaction types, and others described herein, are the subjects of active research and are also finding use in many current areas of application.

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CH5N2 hydrazyl radicals, cations and dication radicals studied by mass spectrometry. Is the N-protonated formaldehyde hydrazon cation +CH2NHNH2 a bridged species?

Cited by 11 publications

References 33 publications

Entropy Effects in the Fragmentation of 1,1-Dimethylhydrazine Ions

Entropy Effects in the Fragmentation of 1,1-Dimethylhydrazine Ions

The formation of NO+ from the reaction of N22+ with O2

Charge permutation reactions in tandem mass spectrometry

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