A mechanistic study for decomposition and reactivity of the C4F9OC2H4O radical derived from HFE-7200 between 200‒400 K

چکیده مقاله

In this study, mechanism of decomposition and reactivity of C4F9OC2H4O• radical obtained from C4F9OC2H5 (HFE-7200), was studied by computational method. All calculations were performed at B3LYP and mPW1PW91 level of theory with 6-311G(d,p) basis set. Four possible pathways were investigated: (i) Reaction with atmospheric O2, (ii) Reaction with atmospheric OH radical, (iii) Release of H radical, and (iv) Rearrangement of the radical in two step and then C-O bond cleavage. These pathways (1), (2), (3), (4A), (4B) and (4C) for the four steps listed, respectively and have energy barriers equal to 6.9, 11.9, 17.7, 30.8, 11.0 and 9.9 kcal.mol-1, respectively. Canonical transition state theory (CTST) was used to calculate rate constants for all steps in the range of 200‒400 K and Arrhenius diagrams were plotted for them. Results showed that reaction with atmospheric O2 with rate constant equal to 48.97 cm3mol-1s-1 is dominant pathway for degradation of C4F9OC2H4O• radical in the atmosphere.