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Mass spectrometry of aralkyl compounds with a functional group–X A reinvestigation of the structure of the [C 8 H 9 ] + ‐ion from 1‐phenylethylbromide and of the molecular ion [C 8 H 8 ] + ˙ from styrene by use of 13 C labelling
Author(s) -
Venema A.,
Nibbering N. M. M.,
de Boer Th. J.
Publication year - 1970
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.1210031215
Subject(s) - cyclooctatetraene , labelling , ion , chemistry , ring (chemistry) , hydrogen , side chain , crystallography , styrene , mass spectrometry , carbon fibers , molecule , materials science , copolymer , organic chemistry , biochemistry , chromatography , composite number , composite material , polymer
Specific 13 C‐labelling in the side‐chain of 1‐phenylethylbromide and of styrene shows that it is not necessary to assume eight‐membered ring structures for the [C 8 H 9 ] + ‐ and [C 8 H 8 ] + + ˙‐ions to explain the almost complete randomization of all hydrogen atoms, as might be concluded from D‐labelling data. It is now suggested that the eight‐membered ring is predominantly present in [C 8 H 9 ] + and [C 8 H 8 ] + ˙ ions of low internal energy. In particular this appears to apply to styrene, which generates a cyclooctatetraene molecular ion with the original side‐chain carbon atoms still linked together, as shown by 13C ‐labelling.