Methyl chloride formation by gas phase thermal chlorine atom reaction with methyl iodide and methyl bromide

被引:12
作者
Goliff, WS
Rowland, FS
机构
[1] Department of Chemistry, University of California, Irvine
[2] Department of Chemistry, University of California, Irvine
关键词
D O I
10.1029/97GL03093
中图分类号
P [天文学、地球科学];
学科分类号
07 ;
摘要
Thermal chlorine atoms react with gaseous CH3I and CH3Br at 295K to produce CH3Cl with yields of 8.6% and 0.6%, respectively. The studies utilized radioactive Cl-38 formed by the Cl-37 (n, gamma) Cl-38 nuclear reaction in gaseous CClF3 at pressures from 760 to 4,000 torr. The initially energetic Cl-38 atoms are thermalized by multiple inelastic collisions with CClF3 prior to reaction with the methyl halide. The reaction rate constant for thermal chlorine attack on CH3Br to form CH3Cl at 295K and 1-5 atmospheres pressure is (2.0 +/- 0.5) x 10(-15) cm(3) molecule(-1) s(-1). The substitution of Cl for Br/I in a methyl halide molecule cannot be a significant source of atmospheric CH3Cl because of its abundance from other sources. However, the replacement of I by CI in other iodohalocarbons might in some cases provide a marker for the presence of atomic chlorine.
引用
收藏
页码:3029 / 3032
页数:4
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