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Investigation of some pentasubstituted 1,4‐dihydropyridines by means of fast ion bombardment, chemical ionization and electron impact mass spectrometry
Author(s) -
Hamdan M.,
Scandola M.,
Tarzia G.
Publication year - 1992
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.1210270614
Subject(s) - electron ionization , chemistry , mass spectrometry , mass spectrum , ion , dissociation (chemistry) , chemical ionization , ionization , fast atom bombardment , collision induced dissociation , ion source , reagent , analytical chemistry (journal) , molecule , tandem mass spectrometry , organic chemistry , chromatography
Positive fast ion bombardment, positive chemical ionization (CI + ) and positive electron impact (EI) ionization mass spectrometry were used to investigate a number of relatively large and structurally related organic molecules. Some of the major dissociation pathways observed in the CH 4 ‐CI + mass spectra are not present under NH 3 ‐CI + conditions, but are obtained in the collision‐induced dissociation (CID) spectrum of the 50 eV MH + molecular ion, formed in the latter reaction. The resemblance between the EI mass spectra and their fast ion bombardment counterparts, the effect of changing the energy of the bombarding Cs + ion beam over the range 2–16 keV and the different degrees of internal excitation of ions formed in different CI reagent gases are discussed.