ISSN:
0030-493X
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The loss of methyl from unstable, metastable and collisionally activated [CH2=CH—C(OH)=CH2]+· ions (1+·) was examined by means of deuterium and 13C labelling, appearance energy measurements and product identification. High-energy, short-lived 1+· lose methyl groups incorporating the original enolic methene (C(1)) and the hydroxyl hydrogen atom (H(0)). The eliminations of C(1)H(1)H(1)H(4) and C(4)H(4)H(4)H(0) are less frequent in high-energy ions. Metastable 1+· eliminate mainly C(1)H(1)H(1)H(4), the elimination being accompanied by incomplete randomization of the five carbon-bound hydrogen atoms. The resulting [C3H3O]+ ions have been identified as the most stable CH2=CH—CO+ species. The appearance energy for the loss of methyl from 1 was measured as AE[C3H3O]+ = 10.47 ± 0.05 eV. The critical energy for 1+· → [C3H3O]+ + CH3· is assessed as Ec ≤ 173 kJ mol-1. Reaction mechanisms are proposed and discussed.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/oms.1210230206
Permalink