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

Relative rate techniques were used to measure k(OH + HFE-7500) = (2.6 +/- 0.6) x 10(-14), k(Cl + HFE-7500) = (2.3 +/- 07) x 10(-12), k[Cl + n-C3F7CF(OC(O)H)CF(CF3)(2)] = (9.7 1.4) x 10(-15), and k[Cl + n-C3F7CF(OC(O)CH3)CF(CF3)(2)] < 6 x 10(-17) cm(3) molecule(-1) s(-1) at 295 K [HFE-7500 = n-C3F7CF(OH5)CF(CF3)(2)] From the value of k(OH + HFE-7500 an estimate of 2.2 years for the atmospheric lifetime of HFE-500 is obtained. Two competing loss mechanisms or n-C3F7CF(OCHO.H-3)CF(CF3)(2) radicais were identified in 700 Torr of N-2/O-2 diluent at 295 K; reaction with 02 and decomposition via C-C bond scission with ko(2)/k(decomp) 0.013 +/- 0.006 Torr(-1). The Cl atom initiated oxidation of HFE-7500 in N-2/O-2 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.