| Abstract: | The following temperature-dependent rate coefficients (k/cm3 molecule–1 s–1) of the reactions of hydroxyl radicals with aliphatic ethers have been determined over the temperature range 247–373 K by a competitive flow technique: diethyl ether,k
OH=5.2×10–12 exp(262±150)/T]; methyln-butyl ether,k
OH=5.4×10–12 exp(309±150)/T]; ethyln-butyl ether,k
OH=7.3×10–12 exp(335±150)/T]; di-n-butyl ether,k
OH=5.5×10–12 exp(502±150)/T] and di-n-pentyl ether,k
OH=8.5×10–12 exp(417±150)/T]. The data have been measured relative to the rate coefficientk(OH + 2,3-dimethylbutane)=6.2×10–12 cm3 molecule–1 s–1 independent of temperature.Previous discrepancies in the room-temperature rate coefficients for the OH reactions with ethyln-butyl ether and di-n-butyl ether, obtained in the flow and static experiments of Bennett and Kerr (J. Atmos. Chem.
8, 87–94, 1989;10, 29–38, 1990) compared with those of Wallingtonet al. (Int. J. Chem. Kinet.
20, 541–547, 1988;21, 993–1001, 1989) and of Nelsonet al. (Int. J. Chem. Kinet.
22, 1111–1126, 1990) have been resolved. The results are considered in relation to the available literature data and evaluated rate expressions are deduced where possible. The data are also discussed in terms of structure-activity relationships. |
