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Novel proximity effects and Ortho interactions in 2,2′‐disubstituted diphenylamines on electron impact
Author(s) -
Ramana D. V.,
Mahalakshi P.
Publication year - 1993
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.1210280209
Subject(s) - electron , chemistry , physics , quantum mechanics
Unexpected ejections of CH 3 NO 2 /[ ˙ CH 3 + ˙ NO 2 ], N 2 O 4 /[ ˙ NO 2 + ˙ NO 2 ] and CH 3 OCH 3 /[ ˙ CH 3 + ˙ OCH 3 ] were observed from the molecular ions of 2‐methoxy‐2′‐nitrodiphenylamine, 2,2′‐dinitrodiphenylamine and 2,2′‐dimethoxydiphenylamine, respectively, under electron impact conditions owing to proximity effects. In other competing fragmentation pathways, novel proximity effects triggered by the ortho interactions leading to the unusual eliminations of [ ˙ CH 3 + H 2 O] from M +˙ of 2‐methoxy‐2′‐nitrodiphenylamine and HNO 3 /[ ˙ NO 2 + ˙ OH] from M +˙ of 2,2′‐dinitrodiphenylamine were observed. Evidence for the interpretation of the main fragmentation pathways was obtained from the metastable ion spectra and high‐resolution mass spectrometry. Confirmation of the structures assigned to the ions was provided by collision‐activated dissociation mass‐analysed ion kinetic energy spectra.