The mechanism and kinetics of the reactions of CF(3)COOCH(2)CH(3), CF(2)HCOOCH(3), and CF(3)COOCH(3) with Cl and OH radicals are studied using the B3LYP, MP2, BHandHLYP, and M06-2X methods with the 6-311G(d,p) basis set. The study is further refined by using the CCSD(T) and QCISD(T)/6-311++G(d,p) methods. Seven hydrogen-abstraction channels are found. All the rate constants, computed by a dual-level direct method with a small-curvature tunneling correction, are in good agreement with the experimental data. The tunneling effect is found to be important for the calculated rate constants in the low-temperature range. For the reaction of CF(3)COOCH(2)CH(3) +Cl, H-abstraction from the CH(2) group is found to be the dominant reaction channel. The standard enthalpies of formation for the species are also calculated. The Arrhenius expressions are fitted within 200-1000 K as kT(1) =8.4×10(-20) T (2.63) exp(381.28/T), kT(2) =2.95×10(-21) T (3.13) exp(-103.21/T), kT(3) =1.25×10(-23) T (3.37) exp(791.98/T), and kT(4) =4.53×10(-22) T (3.07) exp(465.00/T).

The reaction of CHF2OCF2CHFCl with atomic chlorine was studied using B3LYP/6-311G(d,p), BHandHLYP/6-311G(d,p), and M06-2X/6-311G(d,p) methods and further using CCSD(T) and QCISD(T) methods. Two hydrogen abstraction channels were found for the title reaction. Dynamics calculations were followed by means of canonical variational transition state with the small-curvature tunneling correction between 220 and 2,000 K. Our rate constant k = 2.90 × 10(-15) cm(3) molecule(-1) s(-1) is in reasonable agreement with the available data (3.20 ± 0.32) × 10(-15) cm(3) molecule(-1) s(-1) at 296 K. The three-parameter Arrhenius expression (in the unit of cm(3) molecule(-1) s(-1)) for the title reaction is given as k (T) = 1.38 × 10 (-19)  T (2.57) exp (-2622.95/T).

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The hydrogen abstraction reactions of mono‐substituted phenols and nitrogen dioxide may be the sources of HONO and phenoxy radical. Further addition reaction of NO2 and phenoxy radical can form 2‐nitrophenol (2‐NP) and 4‐nitrophenol (4‐NP). The specific formation mechanisms and dynamics of NPs have drawn significant attention in recent days. The promoted reaction mechanisms by water, phenol and intermediate have also been studied. Compared with the naked reaction, the catalytic pathways can reduce the energy barrier from 48.40 kcal/mol to 18.23, 23.03 and 18.87 kcal/mol to form 2‐NP, respectively. Water molecules are the most effective catalysts, and the energy barrier could be further reduced to 8.20 kcal/mol when three water molecules are participating in the reaction. Water molecules can not only promote the formation of 4‐NP, but also simplify the reaction steps. In general, the water molecules serve as catalysts in the formation of NPs. The rate constants of 2‐NP and its hydrates have been predicted. The results are listed as follows: k2‐NP =3.82×10−13; k2‐NP‐1W =2.43×10−7; k2‐NP‐2W =3.39×10−4 cm3molecule−1s−1. The rate constants of mono‐substituted phenols (methylamino phenol, aminophenol and hydroquinone) and NO2 are also predicted by the traditional transitional state theory and variational transition state theory using the B3LYP/6‐311++G(3df,3pd)//6‐311++G(d). For the most dominant path, the rate constants for o/m/p‐methylaminophenol are 1.91×10−14, 4.28×10−20 and 8.78×10−15 cm3molecule−1s−1, respectively.