Rate constants for reactions of OH radicals with some Br-containing haloalkanes |
| |
Authors: | Vladimir L Orkin Victor G Khamaganov |
| |
Institution: | (1) Institute of Energy Problems of Chemical Physics, Russia Academy of Sciences, Leninsky prospect, 38, Bldg. 2, 117829 Moscow, Russia |
| |
Abstract: | Rate constants have been measured for the gas-phase reactions of hydroxyl radical with two halons and three of their proposed substitutes and also with CHClBr-CF3 using the discharge-flow-EPR technique over the temperature range 298–460 K. The following Arrhenius expressions have been derived (units are 10–13 cm3 molecule–1 s–1): (9.3
–0.9
+1.0
) exp{–(1326±33)/T} for CHF2Br; (7.2
–0.6
+0.7
) exp{–(1111±32)/T} for CHFBrCF3; (8.5
–0.8
+0.9
) exp{–(1113±35)/T} for CH2BrCF3; (12.8
–1.2
+1.5
) exp{–(995±38)/T} for CHClBrCF3. The rate constants at 298 K have been estimated to be <2×10–17 cm3 molecule–1 s–1 for CF3Br and CF2Br—CF2Br. The atmospheric lifetimes due to hydroxyl attack have been estimated to be 5.5, 3.3, 2.8, and 1.2 years for CHF2Br, CHFBr—CF3, CH2Br—CF3 and CHClBr—CF3, respectively. |
| |
Keywords: | Hydroxyl radical halon rate constant |
本文献已被 SpringerLink 等数据库收录! |
|