The Energy Surface for Isomeric (1+) Ions: Further Experimental Evidence

Article abstract of DOI:10.1002/oms.1210181221

Mass spectra from collisionally activated dissociation (CAD) of (1+) ions, including isotopically labeled analogs, provide further information on the isomers O(1+)> (a), (b), (c) and (d).Our data generally support the recent conclusions from theory by Radom and coworkers and from experiment by Terlouw, Holmes and coworkers.Most acetyl-containing molecular ions form a ions in high purity only at low energies, consistent with isomerization of higher energy molecular ions to form the more stable enol which dissociates to b.Isomer d, prepared from (ClCH2)2CHOH, undergoes facile hydrogen scrambling, presumably through a degenerate 1,2-hydrogen shift.Theory suggests that c undegoes spontaneous isomerization to a and d; although (1+) ions from BrCH2CHO appear to consist of a and ca.15percent d, the latter are formed without substantial hydrogen scrambling.