Electron impact studies. XCIII. The reactions of negative ions from 3- and 4-nitrophthalic anhydrides

1975 ◽  
Vol 28 (3) ◽  
pp. 563 ◽  
Author(s):  
JH Bowie ◽  
BD Williams
Keyword(s):  
Electron Impact ◽  
Phthalic Anhydride ◽  
Cyclotron Resonance ◽  
Mass Spectra ◽  
Negative Ions ◽  
Negative Ion ◽  
Ion Cyclotron Resonance ◽  
Impact Studies ◽  
Ion Molecule Reactions ◽  
Positive Ions

Possible structures for some rearrangement ions in the negative ion mass spectra of 3- and 4-nitro- phthalic anhydride are suggested from an examination of the + E spectra obtained by the conversion of the negative ions to positive ions by charge-stripping reactions. The reactivities of the non-decomposing negative ions have been investigated by observation of their ion-molecule reactions with the neutral anhydride in the cell of an ion cyclotron resonance spectrometer.

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. 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.

Electron impact studies. CXIII. Aromatic nucleophilic substitution in the gas phase. The dinitrobenzenes. An ion cyclotron resonance study

1977 ◽  
Vol 30 (4) ◽  
pp. 795 ◽  
Author(s):  
JH Bowie ◽  
BJ Stapleton
Keyword(s):  
Nucleophilic Substitution ◽  
Gas Phase ◽  
Electron Impact ◽  
Cyclotron Resonance ◽  
Mass Spectra ◽  
Major Ions ◽  
Abundance Ratio ◽  
Negative Ion ◽  
Ion Cyclotron Resonance ◽  
Aromatic Nucleophilic Substitution

The negative ion mass spectra derived from the three dinitrobenzenes show NO2-, [M-?-NO?]- and M-? as major ions. The i.c.r. spectrum of o- dinitrobenzene shows the formation of the adducts [M+NO2-]-, [M+(M-?-NO?)- ]- and 2M-?, but the m- and p-dinitrobenzenes only produce the adduct [M+NO2-]-. The nucleophile Cl- adds to each of the three dinitrobenzene neutrals in the abundance ratio o >> m ≈ p. Evidence is presented which suggests that the neutral products formed by the reaction between NO2- and o-dinitrobenzene are dinitro- and trinitro-benzenes, whereas those resulting from the interaction of Cl- with o-dinitrobenzene are chloronitrobenzene and a chloro-dinitrobenzene.

Comparison of Five Ionization Methods for Producing Mass Spectra of Typical Organophosphorus Pesticides

1978 ◽  
Vol 32 (4) ◽  
pp. 388-399 ◽  
Author(s):  
Kenneth L. Busch ◽  
Maurice M. Bursey ◽  
J. Ronald Hass ◽  
G. Wayne Sovocool
Keyword(s):  
Electron Impact ◽  
Mass Spectra ◽  
Chemical Ionization ◽  
Organophosphorus Pesticides ◽  
Large Fraction ◽  
Negative Ion ◽  
Oxygen Mixture ◽  
Ion Molecule Reactions ◽  
And Migration ◽  
Positive Chemical Ionization

Positive ion mass spectra obtained by conventional electron impact and by methane chemical ionization were compared with the negative ion mass spectra of 16 typical organophosphorus pesticides using methane, a methane-oxygen mixture, and oxygen as enhancement/reagent gases. In the negative ion spectra, phosphate and phenate anions typically carry a large fraction of the ion current. Displacement of chlorine by oxygen is noted in some cases, and migration of aryl groups from oxygen to sulfur is occasionally noted. Ion-molecule reactions between two species derived from sample molecules have been observed. The sensitivity of the negative ion techniques for the pesticides examined is greater than conventional electron impact or methane positive chemical ionization techniques, and can be up to 800 times more sensitive for some compounds.

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