Electron impact studies. CII. +E spectra from negative ions. Flavones and quinones

1976 ◽  
Vol 29 (1) ◽  
pp. 115 ◽  
Author(s):  
JH Bowie ◽  
T Blumenthal
Keyword(s):  
Electron Impact ◽  
Negative Ions ◽  
Electric Sector ◽  
Impact Studies ◽  
Molecular Anions ◽  
Positive Ion

+ E spectra derived from the molecular anions of flavones and quinones are used to illustrate and compare the resolution and sensitivity of spectra obtained by both magnetic and electric sector scan techniques. Some fragmentations are noted which do not occur in the conventional positive-ion spectra of these compounds.

Electron impact studies. CXI. +E Spectra from negative ions. The retro-Diels-Alder process

1977 ◽  
Vol 30 (3) ◽  
pp. 675 ◽  
Author(s):  
JH Bowie ◽  
AC Ho
Keyword(s):  
Electron Impact ◽  
Negative Ions ◽  
Diels Alder ◽  
Negative Ion ◽  
Impact Studies ◽  
Positive Ion

Abundant peaks produced by retro-Diels-Alder cleavages are observed in the dissociative + E spectrum of a negative ion, whenever such peaks are seen in the corresponding positive-ion spectrum of that compound.

Electron impact studies. XCVI. Negative ion mass spectra of naturally occurring compounds. Nitrophenyl esters derived from long-chain acids andalcohols

1975 ◽  
Vol 28 (5) ◽  
pp. 1011 ◽  
Author(s):  
JH Bowie ◽  
BJ Stapleton
Keyword(s):  
Electron Impact ◽  
Analytical Method ◽  
Mass Spectra ◽  
Molecular Ions ◽  
Negative Ion ◽  
Impact Studies ◽  
Naturally Occurring ◽  
Molecular Anions ◽  
Positive Ion ◽  
Long Chain

The positive ion mass spectra of long-chain alcohols and acids are either devoid of molecular ions or contain such species in low abundance. The negative ion spectra of p-nitrophenyl esters of these compounds exhibit pronounced molecular anions, showing the technique to be a useful analytical method for these classes of compounds.

Electron impact studies. CXVIII. An ion cyclotron resonance study of the reactivity of negative ions derived from ethenetetracarbonitrile. Anionic polymerization in the gas phase

1977 ◽  
Vol 30 (10) ◽  
pp. 2161 ◽  
Author(s):  
JH Bowie
Keyword(s):  
Gas Phase ◽  
Electron Impact ◽  
Anionic Polymerization ◽  
Cyclotron Resonance ◽  
Negative Ions ◽  
Ion Cyclotron Resonance ◽  
Impact Studies ◽  
Stable Adduct ◽  
Ion Cyclotron

.The [M·–l CN·I- species from ethenetetracarbonitrile (tetracyanoethylene) reacts with neutral ethene- tetracarbonitrile to give the stable adduct C11N7-. The decomposing form of this adduct eliminates C2N2 to produce C,9N5- which may react with ethenetetracarbonitrile to yield C15N,9-. Analogous anionic polymerization reactions yield a number of detectable peaks in the i.c.r. spectrum of tetra- cyanoethylene, with the structures of the ions possibly corresponding to a. Diagram Polymerization of this type can also be initiated by other nucleophiles including Cl-, Br-, I- and CF3CO2-.

Electron impact studies. CVIII. Negative-ion mass spectra of the oxime group

1976 ◽  
Vol 29 (11) ◽  
pp. 2437 ◽  
Author(s):  
JH Bowie ◽  
S Janposri
Keyword(s):  
Electron Impact ◽  
Mass Spectra ◽  
Major Product ◽  
Negative Ion ◽  
Oxime Group ◽  
Impact Studies ◽  
Molecular Anions

Molecular anions derived from Ar-CH=NOH systems fragment by the process [MI- → [M-H2O]- to yield pronounced peaks corresponding to [ArCN]-. Molecular anions from Ar(CH2)nC(NOH)Ph (n = 0-2) also eliminate H2O, but the mechanisms are often complex. Possible mechanisms for some of these eliminations are suggested after consideration of the + E spectra of non-decomposing [M?H2O]- ions. A characteristic cyclization/retro process of o-O2NC6H4-CH=CH-C(NOH)R molecular anions produces CHO-CR=N-O- as the major product anion.

Electron impact studies. CIX. The detection of doubly charged negative ions by ion cyclotron resonance spectroscopy

1977 ◽  
Vol 30 (2) ◽  
pp. 417 ◽  
Author(s):  
BJ Stapleton ◽  
JH Bowie
Keyword(s):  
Electron Impact ◽  
Cyclotron Resonance ◽  
Negative Ions ◽  
Alkyl Halides ◽  
Resonance Spectroscopy ◽  
Ion Cyclotron Resonance ◽  
Impact Studies ◽  
Ion Cyclotron ◽  
Doubly Charged

Ion cyclotron resonance allows the sensitive measurement of doubly charged anions at low cell pressures. Evidence is presented which suggests the formation of X-- (X = halogen) ions from alkyl halides.

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