Thermochemical properties of free radicals from G3MP2B3 calculations

✍ Scribed by R. Janoschek; M. J. Rossi

• Publisher: John Wiley and Sons
• Year: 2002
• Tongue: English
• Weight: 179 KB
• Volume: 34
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/kin.10082

✦ Synopsis

Abstract

For a set of 32 selected free radicals, energy minimum structures, harmonic vibrational wave numbers ω~e~, principal moments of inertia I~A~, I~B~, and I~C~, heat capacities C°~p~(T), entropies S°(T), thermal energy contents H°(T) − H°(0), and standard enthalpies of formation Δ~f~H°(T) were calculated at the G3MP2B3 level of theory in the temperature range 200–3000 K. In this article, thermodynamic functions at T = 298.15 K are presented and compared with recent experimental values. The mean absolute deviation between calculated and experimental Δ~f~H°(298.15) values resulted in 3.91 kJ mol^−1^, which is close to the average experimental uncertainty of ± 3.55 kJ mol^−1^. The influence of hindered rotation on thermodynamic functions is studied for isopropyl and tert‐butyl radicals. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 550–560, 2002