Canonical Variational Transition-State Theory Study of the CF₃CH₂CH₃ + OH Reaction

Abstract

Variational transition-state theory rate constants with multidimensional tunneling contributions using the small curvature method have been calculated for the CF3CH2CH3 (HFC-263fb) + OH reaction over a temperature range from 200 to 373 K. The mPW1B95-41.0 hybrid functional, parametrized by Albu and Swaminathan to generate theoretical rate constants nearly identical to the experimental values for the CH3F + OH reaction, has been used in conjunction with the 6-31+G** basis set to explore the potential energy surface of the title reaction. The good agreement found between theoretical predictions and the experimental data available suggests that the present approach is an excellent option to obtain high-quality results at low computational cost for direct dynamics studies of hydrogen abstraction reactions from complex hydrofluorocarbons. The reliability of the structure activity relationship used to estimate rate constant values for OH reactions with hydrofluorocarbons is also discussed in detail.

Gas-phase reaction between calcium monocation and fluoromethane: Analysis of the potential energy hypersurface and kinetics calculations

“…An efficient and straightforward way to dealing with that pitfall was to correct frequencies by means of linear interpolations. 40 The problem was observed to occur more often in the case of the BMK functional. As a matter of fact, we do believe that some discrepancies with the rest of functionals, detected when computing the BMK entrance channel ͑see next section͒ should be ascribed to the unreliable frequencies predicted along the BMK DCP.…”

Computational study on OH radical reaction with CHF2CHFCHF2(HFC‐245ea) between 200 and 400 K

“…Transition state theory (TST), ab initio methods, and density functional theories (DFT) can also be used to compute the rate coefficients of these reactions. Kinetics of these reactions with several HFCs were reported in the literature using these computational methods [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20].…”

Estimation of the ionization potential for polyhalogenated hydrocarbons by weakest bound potential method

“…Thus, the relationship between their structure and properties has gained more and more attention. [1][2][3][4][5][6][7][8][9][10] As a fundamental property of polyhalogenated hydrocarbons, their ionization potential (IP) relates to some important thermodynamic and kinetic properties [11][12][13] and has played a significant role in theory research. [14][15][16][17][18][19][20][21][22][23][24][25] However, being the limitation of experimental conditions, only a small number of their IP values have been experimentally determined.…”

“…Polyhalogenated hydrocarbons including chlorofluorocarbons and bromofluorocarbons have been widely applied to industrial production, and also they result in some environmental problems. Thus, the relationship between their structure and properties has gained more and more attention . As a fundamental property of polyhalogenated hydrocarbons, their ionization potential (IP) relates to some important thermodynamic and kinetic properties and has played a significant role in theory research .…”