Thermochemical Similarities Among Three Reaction Systems: Vinyl + O₂ – Phenyl + O₂ – Dibenzofuranyl + O₂

Abstract

It is interesting to study and compare the thermochemical parameters in the vinyl + O₂, phenyl + O₂ and dibenzofuranyl + O₂ chemical activation reaction systems as well as the corresponding peroxy radical and hydroperoxide adduct dissociations. The analogy in C–O and C–H bond energies, well depths, bond type environment and reaction paths in these three reaction systems suggest a corresponding similarity in the initial reaction kinetics of these unsaturated R• + O₂ reactions. In this study we identify the similarities in thermochemistry, bond energies and reaction kinetics of paths. The similar structures and parameters suggest that calculations on the vinyl system can often serve as surrogate or model for reaction paths and kinetic barriers in the larger phenyl system and the large dibenzofuranyl system for which high-level calculations are difficult. Here the vinyl + O₂ and the phenyl + O₂ systems can be used as model for the dibenzofuranyl + O₂ system.

Keywords:

• Ab-initio
• Density functional theory
• Dibenzofuran oxidation
• Phenyl oxidation
• Thermochemical properties

Notes

^a 1 – Prosen-Rossini (1945); 2 – Prosen et al. (1945); 3 – Chase (1998); 4 – Sebbar et al. (2005a); 5 – Sebbar et al. (2005b); 6 – Turecek-Havlas (1986); 7 – Da Silva et al. (2006); 8 – Cox (1961); 9 – Sebbar et al. (2002a); 10 – Guthrie et al. (1952); 11 – Steele-Chirico (1990); 12 – Chirico et al. (1990); 13 – Sabbah (1991); 14 – Cox et al. (1984); 16 – Ruscic (2001); 17 – Ruscic (2006); 18 – Tsang et al. (1996); 19 – Knyazev-Slagle (1998); 20 – Mebel et al. (1996).

^a Steele and Chirico (1990).

^b Chirico et al. (1990).

^c Sabbah (1991).

^d recommended value.

^a Calculations based on G3 and Turecek and Havlas (1986).

^b Calculations based on da Silva et al. (2006).

^c Calculations based on G3.

^d calculations based on DFT.

^e Calculations based on G3 and Cox (1961).

^f,g See text below

^f site 2,3,4

^g site 1