The mass spectra of cyclobutanol and three 2H labelled analogs have been studied. The losses of C2H4 and C2H5• from the molecular ion involve specific fragmentations. Only CH3• loss from the α-cleaved molecular ion2 clearly involves hydrogen atom scrambling; this fragmentation also proceeds by a specific mechanism involving C-2 and hydroxyl hydrogen atoms. Loss of water from the molecular ion involves all the hydrogen atoms but in a complex, non-random manner.
Reduction of the methylene blue cation during fast atom bombardment was studied in glycerol-thioglycerol and glycerol-nitrobenzyl alcohol matrices. The relative abundances of reduced species are significantly lower in a matrix containing 0.2 m thioglycerol in glycerol than they are in pure thioglycerol. Pure 3-nitrobenzyl alcohol or a glycerol-nitrobenzyl alcohol mixture is a less effective matrix material. These results are discussed in terms of a postulated mechanism for the formation of the reduced dye cation species.
The EI induced fragmentation of 2-pyrimidinone (1) and several N(1)-substituted derivatives has been studied. Principal fragmentation pathways have been identified using 2H labelling, metastable defocussing, and exact mass measurements.The fragmentation of 1 parallels that of cytosine. The hydrogen atom at C(4), and not the tautomeric hydrogen, is involved in the formation of the prominent [M – H]+ peak in the spectrum of 1; subsequent fragmentations of the [M – H]+ moiety contribute significantly to the spectrum.Side chain eliminations predominate in the mass spectra of the N(1)-substituted derivatives, but peaks characteristic of the pyrimidinone nucleus are observable in every case. Alternative structures for the [M – H]+ entity formed by H• loss from the substituent are proposed for the N-phenyl and N-benzyl compounds.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.