Theoretical Study of the Heats of Formation of SF, FSO, FSO2 and HSO Radicals

M. P. BADENES; M. E. TUCCERI; C. J. COBOS

Zeitschrift für Physikalische Chemie

Año: 2000 vol. 214 p. 1193 - 1208

0942-9352

Standard heats of formation of SF, FSO, FSO2 and HSO radicals have been calculated with the hybrid B3LYP density functional using extended basis set and qith CBS-4M, CBS-q, CBS-Q and CBS-QB3 model chemistries. The values computed from bond dissociation enthalpies and atomization energies are typically 2-3 kcal mol-1 higher than those obtained from a large number of isodesmic reactions. Applications of isodesmic reactions calculations with energies computed at the CBS-q level of theory yielded our best values of 0.2±1.0, -69.9±2.0, -96.2±3.0, and -4.4±1.5 kcal mol-1 for SF, FSO, FSO2 and HSO respectively. The values for the FSO and FSO2 reduce markedly the literature uncertainties while the values for the SF and HSO are in good agreement with previous ab initio estimates.