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Structure determination of [C 3 H 3 N 2 ] + ions, formed from monosubstituted pyrazoles C 3 H 3 N 2 R, by collision‐induced dissociation mass spectrometry
Author(s) -
Van Tilborg M. W. E. M.,
Van Thuijl J.
Publication year - 1984
Publication title -
organic mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 0030-493X
DOI - 10.1002/oms.1210191108
Subject(s) - ion , deuterium , chemistry , dissociation (chemistry) , mass spectrum , analytical chemistry (journal) , collision induced dissociation , kinetic isotope effect , isotope , spectral line , crystallography , mass spectrometry , atomic physics , physics , tandem mass spectrometry , organic chemistry , chromatography , quantum mechanics , astronomy
[C 3 H 3 N 2 ] + ions have been generated under electron impact conditions from some monosubstituted pyrazoles C 3 H 3 N 2 R. Collision‐induced dissociation (CID) mass spectra of deuterium‐labelled precursors suggest that the majority of the [C 3 H 3 N 2 ] + ions formed from 1‐nitro‐ and 4‐bromo‐pyrazole retain their cyclic structure, whereas the ions from 3(5)‐bromopyrazole are mainly linear. This is confirmed by the relative values observed for the overall cross‐sections for CID and for ion loss. An isotope effect of the order of 1.5–1.9 has been found for the collision‐induced loss of H ˙ from [C 3 H 3 N 2 ] + , generated from 3(5)‐ and 4‐bromopyrazole.