Atmospheric Reactions of HFE-7100 with HO2 and NH2 radicals: Kinetics Mechanism and Atmospheric implications

In recent pasts, HFE-7100 finds its industrial applications like cleaning electronic equipment, secondary refrigerant and carrier fluids for lubricant. Detailed theoretical investigations have been carried out on the mechanism, kinetics and thermochemistry of the gas-phase reactions between CF3CF2CF2CF2OCH3 (HFE-7100) and HO2 and NH2 radicals using DFT-based M06-2X/6-311++G(d,p) level of theory. Two important H abstraction channels have been identified and one transition state has been located for each reaction channel. The pre-reactive and post-reactive complexes are validated at entrance and exit channels, respectively. The potential energy surface of the HFE-7100 with HO2 and NH2 radicals has been investigated using DFT method. The rate constants of the two reactions are computed over the temperature range of 250–450 K for the first time. Our results suggest that hydrogen abstraction by NH2 radical is likely the dominant route for the atmospheric oxidation of HFE-7100 under reaction conditions. Keywords: Segregated HFE; M06-2X; DFT; Rate constant; Amino radical