ISSN:
1434-193X
Keywords:
Radicals
;
Dioxygen trapping
;
Radical reactions
;
Singlet-triplet splitting
;
Thermochemistry
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
---From the oxygen and temperature dependence of the trapping rate of 7,7-difluorobenzocyclopropene (1) in the range 180-240 °C, the energy profile of the equilibrium 1 →←2 has been obtained. From the heat of hydrogenation of 1, its heat of formation is derived (ΔHof = +3.8 kcal·mol-1), as a result of which the heat of formation of the singlet state of the diradical 2 is estimated as 25.7 kcal·mol-1. Whereas the trapping experiments demonstrate unambiguously a triplet ground state for 2, only a lower limit for the singlet-triplet splitting (〉 6 kcal·mol-1) can be given.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
