Unimolecular and bimolecular reactions of the β-distonic ion CH2CH2OCH+2 and its deuterated derivatives

Wittneben, Doris; Grützmacher, Hans‐Friedrich

doi:10.1016/0168-1176(90)85094-i

Cited by 38 publications

(19 citation statements)

References 17 publications

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“…• CH 2 CH 2 OCH 2 + distonic ion 2. 2,3,6 However, it will be shown in this study that the m/z 58 ions do not have a single structure, but that, besides ion 2, a minor amount of ion CH 3 OCHCH 2 +• (1) is also present.…”

Section: Resultsmentioning

confidence: 63%

“…In order to distinguish between isomeric ions, it is often possible to find some simple and practical specific reactions. Several bimolecular reactions of the C 3 H 6 O +• ions, CH 3 OCHCH 2 +• (1) 1 and • CH 2 CH 2 OCH 2 + (2), 2,3 have been described. The radical cation of methyl vinyl ether 1 gives rise to crossed cycloaddition-cycloreversion reactions with alkenes, 1 whereas the reactions of distonic ion 2 are dominated by the transfer of ionized ethylene.…”

Section: Introductionmentioning

confidence: 99%

“…The radical cation of methyl vinyl ether 1 gives rise to crossed cycloaddition-cycloreversion reactions with alkenes, 1 whereas the reactions of distonic ion 2 are dominated by the transfer of ionized ethylene. 2,3 In this work, the behavior of both ions, in the presence of four selected reactants (acetonitrile, formaldehyde, propene and labeled ethylene), is compared in order to characterize these ions.…”

Section: Introductionmentioning

confidence: 99%

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The C3H6O+• fragment from 1,4-dioxane+• revisited

Thissen

Audier

Chamot‐Rooke

et al. 1999

Eur. J. Mass Spectrom.

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In the cell of a Fourier transform ion cyclotron resonance mass spectrometer, the reactions of C 3 H 6 O +• (m/z 58) isomer ions CH 3 OCHCH 2 +• (1) and • CH 2 CH 2 OCH 2 + (2) with selected neutral molecules serve to distinguish clearly between these structures. It is shown that, contrary to earlier assumptions, the m/z 58 ions formed by fragmentation of 1,4-dioxane +• do not correspond to a single structure. The main component corresponds to structure 2, but structure 1 is also present to the extent of about 7%. The mechanism of fragmentation is discussed.

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Section: Resultsmentioning

confidence: 63%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The C3H6O+• fragment from 1,4-dioxane+• revisited

Thissen

Audier

Chamot‐Rooke

et al. 1999

Eur. J. Mass Spectrom.

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“…The β-distonic ion CH 2 =O + CH 2 CH 2 • dissociates by loss of a hydrogen atom or a molecule of carbon monoxide. 46 The latter reaction involves formation of ionised ethane and deserves inclusion in this review because it is unusual and also because this pathway closely resembles those for many eliminations of neutral alkanes from ions. The total heat of formation of ionised ethane (1028 kJ mol -1 ) and carbon monoxide (-110.5 kJ mol -1 ) is 917.5 kJ mol -1 , but the combined heats of formation of ionised carbon monoxide (1241.5 kJ mol -1 ) and ethane (-84 kJ mol -1 ) is 1157.5 kJ mol -1 .…”

Section: Ch 3 Ch 3 +• Formation From Ch 2 =O + Ch 2 Ch 2 •mentioning

confidence: 99%

EMS Account: Alkane eliminations from ions in the gas phase

McAdoo

Bowen

1999

Eur. J. Mass Spectrom.

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A review of reactions involving the elimination of an alkane from a variety of even and odd electron ions in the gas phase is presented. Particular attention is focused on the mechanisms of these reactions and the role of ion-neutral complexes. Alkane eliminations from open shell species derived by ionisation of ketones, ethers, alcohols, amines, alkanes and alkyl-substituted cycloalkanes are considered, together with ethane loss from the distonic ion CH 2 =O + CH 2 CH 2 •. These reactions are, without obvious exception, complex-mediated. Elimination of alkanes from an assortment of closed shell ions, including protonated acetaldehyde, dialkylmethylene immonium ions, onium ions, quaternary ammonium cations, alkoxide anions, enolate anions and deprotonated amines are also discussed. These reactions tend to be complex-mediated when heterolytic bond cleavages are possible. When such cleavages are not energetically feasible, alkane eliminations can take place by asynchronous, concerted mechanisms. Several factors affect the relative rates of alkane elimination compared to those of competing alkyl radical loss in the dissociations of these radical-cations; these factors include the internal energy of the ion, the size of the ionic and neutral partners, the initial orientation of these components and the binding energy of the complex. In addition, primary and secondary isotope effects influence both alkyl radical and alkane elimination. When alkanes are eliminated from radical-cations, reaction between the partners is often quickly overtaken in importance by direct separation of the components if the internal energy is raised either by increasing the energy of the ionisation process or by prior isomerisation over an energy barrier. This trend demonstrates that the attractions between the partners are easily overcome by quite small amounts of excess energy in the system. Typical binding energies between the ionic and non-polar neutral partners lie in the range 0-30 kJ mol-1 at distances at which covalent forces cease to be significant. Illustrative examples are given to show how studies of reactions involving ion-neutral complexes offer a means of obtaining information on the dynamics of short range interactions between ions and neutrals, including the motions of the partners relative to each other.

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“…For example, most of the reactions of the thoroughly studied9-12 ion 'CH,CH,CH,CO+ apparently occur3~'~' ' *' ' via initial addition of the attacking nucleophile to the unsaturated charged center, followed by a radical reaction. A novel sulfur-containing distonic ion, the methyl- enedimethylsulfonium ion, (CH3)2S+-CH2' (m/z 76), was recently synthesized in the gas phase.6*' 3 * 1 4 Th' 1s ion contains a coordinatively saturated charge site and cannot form an additional bond with a neutral reagent molecule. In our initial report of the synthesis of (CH3)2SC-CH2', we demonstrated that this ion nevertheless reacts with dimethyl disulfide to give a sole product which corresponds to abstraction of a thiomethyl radicaL6 We report here a general survey of the bimolecular reactivity of this ion.…”

Section: Introductionmentioning

confidence: 99%

Radical‐type reactivity of the methylenedimethylsulfonium ion, (CH₃)₂S⁺CH₂^˙

Smith

Chyall

Stirk

et al. 1993

Org. Mass Spectrom.

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A 6 initio molecular orbital calculations at the MP2/6-31G*//6-31G* + ZPVE level of theory suggest that the ion (CH,),S+--CH,'is 75 k J mol-' higher in energy than ionized ethyl methyl sulfide. However, this distonic ion is stable toward isomerization to the conventional structure: the two ions show distinctly different reactivity in a dual-cell Fourier transform ion cyclotron resonance mass spectrometer. Molecular orbital calculations further indicate that the charge site of the ion is on the sulfur atom whereas the odd-spin density is localized on the CH, group. The chemical properties of the ion reflect this description. The coordinatively saturated sulfonium charge site is chemically inert. This radical cation possesses unique chemical reactivity in that its reactions are associated with the radical site. Most of these reactions involve a homolytic bond cleavage in the neutral molecule, resulting in abstraction of an atom or a radical by the ion. The reaction efticiency correlates with the homolytic bond dissociation energy of the bond being broken in the neutral molecule, suggesting a simple radical abstraction mechanism for these reactions. Hence, the methylenedimethylsulfonium ion is best described as on electrophilic radical with an inert charge site.

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Unimolecular and bimolecular reactions of the β-distonic ion CH2CH2OCH+2 and its deuterated derivatives

Cited by 38 publications

References 17 publications

The C3H6O+• fragment from 1,4-dioxane+• revisited

The C3H6O+• fragment from 1,4-dioxane+• revisited

EMS Account: Alkane eliminations from ions in the gas phase

Radical‐type reactivity of the methylenedimethylsulfonium ion, (CH₃)₂S⁺CH₂^˙

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Unimolecular and bimolecular reactions of the β-distonic ion CH2CH2OCH+2 and its deuterated derivatives

Cited by 38 publications

References 17 publications

The C3H6O+• fragment from 1,4-dioxane+• revisited

The C3H6O+• fragment from 1,4-dioxane+• revisited

EMS Account: Alkane eliminations from ions in the gas phase

Radical‐type reactivity of the methylenedimethylsulfonium ion, (CH3)2S+CH2˙

Contact Info

Product

Resources

About

Radical‐type reactivity of the methylenedimethylsulfonium ion, (CH₃)₂S⁺CH₂^˙