Dy-11.-1 –11.-12.CH3F+Cl-12.a part of the chlorine released from chlorofluorocarbons is stored in the HCl reservoir at higher altitudes, over 50 km [1]. The tropospheric concentrations of HCl attain specially higher values either near the surface of remote ocean regions or inside the coastal urban places. Hence, the kinetics of your reactions of HCl with such reactive species as the halogenated methyl radicals is of some value for modeling and kinetic description with the complicated processes occurring in the polluted atmosphere. In addition, towards the finest of our knowledge there is absolutely no experimental info around the kinetic investigations of the reactions CH2X + HCl (X 0 F, Cl and Br) performed below common atmospheric situations. The price constants, for the reverse reactions derived on the basis on the calculated equilibrium constants might be expressed inside the following type: k H2 F ?HCl??2:88 ?10?three ? =300?:02 ?exp 1255=T?cm3 molecule? s? ?0?H-13.0 2 three 41000K/TFig. three Arrhenius plot for the CH3F + Cl reaction comparing the obtainable results of kinetic measurements with obtained theoretically in this studyk H2 Cl ?HCl??2:42 ?10?3 ? =300?:57 ?exp 2100=T?cm3 molecule? s? ?1?k H2 Br ?HCl??two:21 ?ten?3 ? =300?:69 ?exp 1485=T?cm3 molecule? s? : ?two?The calculated rate constants for the forward processes, CH3F + Cl and CH3Br + Cl well describe the reaction kinetics within the temperature selection of 250?00 K. Within the case of CH3Cl + Cl, the derived kinetic expression (ten) describes pretty well the reaction kinetics within a whole temperature variety.Formula of 1785259-87-1 As a result, the equations (ten?2) ought to reliably describe the values and temperature dependence of k(CH2X+HCl) within the temperature ranges provided above. The kinetics from the hydrodehalogenation of CF2ClBr with hydrogen has been experimentally studied by Yu et al. [66] in the high temperatures of 673 ?973 K. In their kinetic computational model, the temperature dependence from the rate continuous for reaction CH2F + HCl was described by the Arrhenius equation of 9.56?0-13 xp(-1225/T) cm3molecule-1s-1 estimated by referring to the analogous reactions from the halogenated methyl radicals with hydrogen bromide [66]. This results in values of the price constant k(CH2F+HCl) of 1.66?0-13, 2.06?0-13 and 2.45?0-13 cm3molecule-1s-1 at 700, 800 and 900 K, respectively. These values are about two times reduced than those obtained within this study. Kinetic isotope impact The substitution of a hydrogen atom by deuterium modifications the physical properties on the molecule.Formula of 4-Formylbenzenesulfonic acid In consequence, theobtained by Tschuikow-Roux et al.PMID:35954127 [33]. The temperature dependence of k(CH3Br+Cl) is often described as: k H3 Br ?Cl??six:26 ?10?2 ? =300?:82 ?exp 795=T?cm3 molecule? s? : ??Benefits of the theoretical investigations indicate a nonArrhenius behavior of the reaction kinetics, in particular at higher temperatures. That is in line with conclusion of Piety et al. [37], nonetheless outcomes on the other experimental investigations don’t confirm a curvature with the Arrhenius plot. The temperature dependence of the rate continuous predicted by Eq. 9 is steeper than that derived by Piety et al. [37] and likely overestimates reaction rate at high temperatures. Reactions CH2F/CH2Cl/CH2Br + HCl The values on the enthalpy of formation and vibrational levels with the reactants and products calculated at the G2 level are in reasonable agreement with those obtained experimentally. 1 can expect that the calculated values from the thermodynamic functions and equilibrium constants for the reactions below i.
