Atmospheric chemistry of CF3(CX2)(2)CH2OH: rate coefficients and temperature dependence of reactions with chlorine atoms and the subsequent pathways of alkyl and alkoxy radicals (X = H, F)

作者：Bai, Feng-Yang; Liu, You-Jun; Wang, Xu; Sun, Yan-Qiu; Pan, Xiu-Mei^*

来源：RSC Advances, 2016, 6(68): 63954-63964.

DOI：10.1039/c6ra10840g

• GLOBAL WARMING POTENTIALS
• TRANSITION-STATE THEORY
• CHEMICAL-REACTION RATES
• OH RADICALS
• HYDROGEN ABSTRACTION
• MOLECULAR CHLORINE
• CL ATOMS
• KINETICS
• REARRANGEMENT
• CF3CH2CH2OH

The atmospheric and kinetic properties of CF3(CX2)(2)CH2OH (X = H, F) with chlorine atoms were studied by density functional and canonical variational transition state theories in conjunction with the small-curvature tunneling correction. The minimum energy path was obtained by the CCSD(T)/6-311++ G(d,p)//B3LYP/6-311G( d,p) method. The H-abstraction channel from the -CH2O- group was found to be the dominant channel, whereas that from the -OH site of the title reactions may be negligible because of the high barrier. All rate constants computed within 200-1000 K are in reasonable agreement with the available experimental values. The degradation mechanism of CF3(CX2)(2)CH2OH is discussed. The subsequent pathways of the CF3(CX2)(2)(CHOH)-H-center dot and CF3(CX2)(2)C(O-center dot)HOH radicals were studied. The atmospheric lifetime and global warming potentials (GWPs) of CF3(CX2)(2)CH2OH were computed, and it is shown that fluorine substitution may increase the lifetime and GWPs. It is also indicated that fluorine substitution may decrease the reactivity. The reaction enthalpies and reaction Gibbs free energies for all relevant reactions were discussed. The rate coefficient expressions for the title reactions obtained are kT(1) = 5.75 x 10(-17)T(2.26) exp(428.02/T) and k(T2) x 1.30 x 10(-17)T(1.96) exp(67.40/T) per cm(3) per molecule per s.

• 出版日期2016
• 单位中国人民解放军空军航空大学; 东北师范大学