O-O Bond Dissociation Enthaltpy in Perfluoromethyl Fluorocarbonyl Peroxide, CF3OOC(O)F. A Density Functional Quantum Chemical Analysis

ERBEN, M. F.; DELLA VÉDOVA, C. O.

Journal of the Argentine Chemical Society

Asociación Química Argentina

Lugar: Buenos Aires; Año: 2004 vol. 92 p. 133 - 138

0365-0375

  Density functional at the B3LYP levels of theory using the Pople´s 6-311+G(3df) basis sets and the Dunning´s aug-cc-pVTZ correlation consistent basis sets have been employed to determine the enthalpy of formation (DHf0(298)) of CF3OOC(O)F at 298 K, using the isodesmic reaction CF3OOCF3 + FC(O)OOC(O)F ® 2 CF3OOC(O)F. Thus, the B3LYP/6-311+G(3df) and B3LYP/aug-cc-pVTZ methods yield DHf0(298) values of –273.3 and –273.2 kcal mol-1, respectively. From the reported DHf0(298) for CF3O· and FC(O)O· radicals, bond energy dissociation (DO-O) values of 38.3 and 38.2 kcal mol-1 are deduced for CF3OOC(O)F, which are in agreement with the reported value for related peroxides. Also, calculations for the enthalpy change in the peroxide bond excision reaction were performed at the B3LYP and B3PW91 using several basis sets. The corresponding DO-O values obtained using these enthalpy changes are too low independently of both basis sets and method of calculation used for the calculation.