ISSN:
0947-3440
Schlagwort(e):
Diradicals
;
Dioxygen trapping
;
Diradical well
;
Supercritical fluids
;
Radicals
;
Chemistry
;
Organic Chemistry
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
From the O2-dependence of the trapping rate of 1,1-difluoro-2,3-diphenylcyclopropane in supercritical CO2 in the temperature range 110-180°C and the rates of its geometrical isomerization and racemization of the trans-isomer, the energy profile for the geometrical isomerization is derived. Assuming that 7 is a common intermediate, the temperature dependence of the ratio of the rates of isomerization/racemization leads to a lowering of 1.2 kcal · mol-1 for the activation energy for the disrotatory cyclization of the intermediate diradical compared to the conrotatory mode. The energy barriers associated with cyclization of the diradical amount to 2.1 and 0.9 kcal · mol-1, respectively.
Zusätzliches Material:
7 Tab.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/jlac.199719970707
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