ISSN:
0030-493X
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Ethenol, 1-d-ethenol, O-d-ethenol and Z-2-d-ethenol were prepared by pyrolysis of corresponding 5-norbornenols at 800°C/2 × 10-6 Torr. The most important fragments in the electron impact mass spectrum of ethenol are [C2H3O]+ and CHO+ and CH3·. The hydrogen atom eliminated from the molecular ion comes mainly from the hydroxyl group (68%) and to a lesser extent from C(1) (25%) and C(2) (7%). The loss of the hydroxyl hydrogen is preceded by rate-determining migration of the hydrogen atom from C(1) onto C(2) to yield CH3C=OH+·ions that decompose to CH3CO+ and H·. The loss of deuterium from O-d-ethenol shows a very small primary isotope effect (kH/kD=1.07), whereas a significant effect is observed for the loss of hydrogen from 1-d-ethenol (kH/kD=1.28). The appearance energy of [C2H2DO]+ from 1-d-ethenol, AE=11.32 eV, gives a critical energy for the hydrogen loss, E=203 kJ mol-1, which is 90 kJ mol-1 above the thermochemical threshold for CH3CO++H·. The appearance energy of CDO+ from 1-d-ethenol was measured as 12.96±0.07 eV, which sets the barrier to isomerization to CH3CDO+· at 1121 kJ mol-1. The ionization energy of ethenol was found to be 9.22±0.03 eV.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/oms.1210190904
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