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The distonic ions HO + CHCH 2 C ˙ H 2 and CH 3 C(O + H)CH 2 C ˙ H 2
Author(s) -
McAdoo David J.,
Hudson Charles E.,
Traeger John C.
Publication year - 1988
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.1210231105
Subject(s) - photoionization , chemistry , ion , deuterium , radical , standard enthalpy of formation , crystallography , medicinal chemistry , stereochemistry , atomic physics , ionization , physics , organic chemistry
The distonic ions HO + CHCH 2 C ˙ H 2 (1) and CH 3 C(O + H)CH 2 C ˙ H 2 (2) were directly generated, their decompositions characterized and their appearance energies determined by photoionization. Heats of formation derived from the appearance energies were 757 kJ mol −1 for 1 and 692 kJ mol −1 for 2. Deuterium labeling demonstrates that both ions decompose at low energies in the same ways as their isomers with the same skeletal structures, consistent with proposals that 1 and 2 are intermediates in the decompositions of those systems. Surprisingly, the values of the translational energy releases accompanying the formation of CH 3 CO + and C 2 H 5 CO + from 2 appear to be inversely proportional to the available excess energy. The 1,2‐H‐shift RC(O + H)CH 2 C˙H 2 → RC(O + H)C˙HCH 3 is compared to the corresponding, non‐occurring 1,2‐H‐shift in alkyl free radicals.