Electron impact studies. LVI. The fluorenyl and phenalenyl cations. The application of metastable characteristics

Abstract

A study of the abundances of certain metastable peaks formed by the de- composition of ions in the first and second field-free regions of a double-focusing mass spectrometer has shown that the M-1 ions (m/e 165) in the mass spectra of fluorene and phenalene have different structures. Correlations based on these structures have been obtained for C13H9+ species formed from different systems.

Electron impact studies—LXVII. The mass spectra of alkyl‐1,3‐dithianes

“…The metastable-defocusing unit has been described previously. 12 The unlabelled compounds (1),14 (V)15 and (IX)5 were prepared by reported procedures. The labelled compounds (111), (IV), (VII), (VIII), (XI) were prepared in the same manner as the unlabelled compounds, using the appropriately labelled propane-l,3-dithiols.…”

Thermal, photochemical, and electron impact induced transformations of 1, 2-benzisoxazolin-3-ones and related heterocyclic compounds

“…The mass spectrum of I demonstrates a similar initial loss of Ng which is followed by the A > 0-YH3 I II expulsion of CO. A reasonable structure for the (M-Ng)^" species is ionized II, based on its subsequent fragmenta tion and the known mass spectral decomposition of II. A similar parallel has been noted (8) VIII 19 Recently, the mass spectrum of thiophene-2,5-Cg was studied to determine the possible occurrence of a similar transformation upon electron Impact (15). An intense fragment ion in the mass spectrum of thiophene (l6) is CHS"^, which, in the case of the labelled material, was found to contain a significant amount of carbon-12.…”

“…Since these ions also appear in the spectrum of XI, but not in that of X, it has been concluded that Xlb partially rearranges to ionized XII prior to fragmentation, but that Interconversion of Xia and Xlb does not occur. The formation of the ions at m/e 166 and m/e I65 appears to be a general fragmentation pathway characteristic of a large variety of dlphenyl-substltuted X XI XII Xia Xlb heterocyclic compounds and has been studied in considerable detail (19).…”

Electron‐impact studies XCV–skeletal rearrangement fragments in the mass spectra of 3,5‐ diphenylisoxazole and 3,5‐ diphenylpyrazole

“…It is probable that the benzoyl azirine (11) is an intermediate in the various thermal processes.cf. 12 In earlier reports3, 13 correspond to a 2,3-diphenylazirine ion radical, i.e. the molecular ion of V, and that the decomposing form of the [C13Hs]+ ion had the properties of a phenalenyl rather than a fluorenyl cation.…”