Atmospheric Chemistry of HFE-7500 [n-C3F7CF(OC2H5)CF(CF3)2]: Reaction with OH Radicals and Cl Atoms and Atmospheric Fate of n-C3F7CF(OCHO•)CF(CF3)2 and n-C3F7CF(OCH2CH2O•)CF(CF3)2 Radicals

Publisher Website
Google Scholar
Abstract
Relative rate techniques were used to measure k(OH + HFE-7500) = (2.6 ± 0.6) × 10-14, k(Cl + HFE-7500) = (2.3 ± 0.7) × 10-12, k[Cl + n-C3F7CF(OC(O)H)CF(CF3)2] = (9.7 ± 1.4) × 10-15, and k[Cl + n-C3F7CF(OC(O)CH3)CF(CF3)2] < 6 × 10-17 cm3 molecule-1 s-1 at 295 K [HFE-7500 = n-C3F7CF(OC2H5)CF(CF3)2]. From the value of k(OH + HFE-7500) an estimate of 2.2 years for the atmospheric lifetime of HFE-7500 is obtained. Two competing loss mechanisms for n-C3F7CF(OCHO•CH3)CF(CF3)2 radicals were identified in 700 Torr of N2/O2 diluent at 295 K; reaction with O2 and decomposition via C−C bond scission with kO2/kdecomp = 0.013 ± 0.006 Torr-1. The Cl atom initiated oxidation of HFE-7500 in N2/O2 diluent gives n-C3F7CF(OC(O)CH3)CF(CF3)2 as the major product and n-C3F7CF(OC(O)H)CF(CF3)2 as a minor product. The atmospheric oxidation of HFE-7500 gives n-C3F7CF(OC(O)CH3)CF(CF3)2 and n-C3F7CF(OC(O)H)CF(CF3)2 as oxidation products. The results are discussed with respect to the atmospheric chemistry and environmental impact of HFE-7500.

This publication has 25 references indexed in Scilit: