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Electron impact and ammonia chemical ionization mass spectra of n ‐azabicyclo[ m .2.0]alkan‐( n + 1)‐ones ( m = 3–6, n = 6–9)
Author(s) -
Pihlaja Kalevi,
Vainiotalo Pirjo,
Bernáth Gábor,
Göndös György,
Gera Lajos
Publication year - 1986
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.1210210202
Subject(s) - electron ionization , ion , chemistry , mass spectrum , fragmentation (computing) , moiety , spectral line , ionization , cyclohexene , ammonia , analytical chemistry (journal) , chemical ionization , stereochemistry , physics , organic chemistry , astronomy , computer science , catalysis , operating system
Electron impact induced fragmentation of the title compounds obeys a route where the lactam moiety, OCNH, is cleaved first, with the accompanying formation of a cycloalkene ion. This can be verified by low‐resolution, high‐resolution, B / E and B 2 / E spectra as well as by collisional activation spectra of, for example, the ions m / z 82 and 67 from 7‐azabicyclo[4.2.0]octan‐8‐one and from cyclohexene. The only, and fairly weak, fragment ions including O and N are [C 3 H 3 O]+, [C k H 2 k ‐2 N] + ( k = 5–8) and [C 3 H 6 N] + . The ammonia chemical ionization spectra are also characteristic for all four lactams and show the same dominant ions in all cases, namely [M + 1] + , [M + 1 + NH 3 ] + ˙ and [2 M + 1] + ˙.