| The degradation mechanism and kinetics of two important organics in atmosphere,benzyl alcohol and isopropyl nitrate,were studied in this thesis.?1?The hybrid meta-density functional theory?M06-2X?and the conventional transition state theory were employed to study the mechanism and kinetics of the reaction of benzyl alcohol with the OH radical.As the OH radical approaches benzyl alcohol,there are six van der Waals complexes are formed,then the OH radical may abstract the H atoms from the-CH2OH group and the benzene ring,or adduct to the C atoms of the benzene ring.The hydrogen abstraction from the-CH2OH group and the ipso and ortho C atom addition are dominant.The calculated overall rate constant is 2.61×10-1111 cm3 molecule-11 s-1,and the branching ratios of the hydrogen abstraction and the addition reactions are 0.23 and 0.77,respectively.At 298 K,as the temperature rises from 250 to 400 K,the branching ratio of the hydrogen abstraction reaction increases while that of the addition reaction decreases.The calculation results are in good agreement with the available experimental values.?2?The reaction mechanism and kinetics of isopropyl nitrate with OH radical have been studied by the hybrid meta density functional theory?M06-2X?combined with the conventional transition state theory.The results show that several reaction complexes are formed through the van der Waals interaction,and starting from these complexes,the OH radical may abstract the H atoms from the tertiary or the methyl carbon atoms,which accounts for 82%and 18%of the product distribution respectively at room temperature.The dominant products are acetone,NO2,and H2O which result from the tertiary-H abstraction,and the acetone yield decreases in the temperature range from 250 K to 500 K.The overall rate constant is 7.4×10-13cm3molecule-1s-1at 298 K.The calculated rate constant and products branching ratio are in agreement with the available experimental values. |
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