Density functional computational thermochemistry: Accurate determination of the enthalpy of formation of perfluoropropane from DFT and ab initio calculations on isodesmic reactions

Ventura ON; Segovia M

Chemical Physics Letters, Vol.403, No.4-6, 378-384, 2005

DOI10.1016/j.cplett.2005.01.041 Export Citation

Density functional computational thermochemistry: Accurate determination of the enthalpy of formation of perfluoropropane from DFT and ab initio calculations on isodesmic reactions

Ventura ON, Segovia M

The experimental enthalpy of formation of perfluoropropane (C3F8), reported originally as -1729 kJ/mol and latter corrected to -1784.7 kJ/mol, is reexamined at the light of density functional and model chemistry (G3, CBS-4, CBS-Q) calculations of several isodesmic reactions relating C3F8 to smaller fluoroalkanes. The average enthalpy of formation of C3F8 obtained from all reactions studied was -1739 +/-12 kJ/mol at the DFT level and -1748 +/- 12 kJ/mol at the ab initio level, thus ruling out the larger experimental value. A value of -1732 +/- 5 kJ/mol is recommended from careful analysis of the theoretical results. (C) 2005 Published by Elsevier B.V.