Mass Spectra of 1,2,5-Selenadiazoles and their Oxygen and Sulfur Analogues.

Mass spectrometric studies of elusive molecules that contain an N+-X? bond

“…Ions of CHNO composition can also be prepared by dissociative ionization of 1,2,5-oxadiazole (Pedersen et al, 1975). However, the actual structure of the so-produced radical cations was not discussed at the time and only the mass spectrum of the heterocyclic precursor was reported.…”

“…Pedersen et al have also studied the dissociative ionization of 3,4-disubstituted-1,2,5-oxadiazoles, such as the dimethyl (27) and the diphenyl (28) species (Pedersen et al, 1975). In order to establish the structures of the ions produced from 27 to 28, we have recently recorded their CA spectra and the observed fragmentations have been interpreted on the basis of the RCNO connectivities (R: H, CH 3 and Ph) (Gerbaux, 1999).…”

Mass Spectra of Some 4- and 5-Substituted Derivatives of Benzoselenadiazoles

“…Although the mass spectra of heterocyclic oxygen and sulphur compounds have been intensively investigated [1], limited data are available in the literature on the mass spectra of benzoselenadiazoles [2,3]. We have prepared new compounds of some 4-and 5-substituted derivatives of benzoselenadiazoles and in order to prove their structures we used mass spectrometry and 1 H a 13 C NMR spectroscopy.…”