標題: Direct kinetic measurement of the reaction of the simplest Criegee intermediate with water vapor
作者: Chao, Wen
Hsieh, Jun-Ting
Chang, Chun-Hung
Lin, Jim Jr-Min
應用化學系
Department of Applied Chemistry
公開日期: 13-Feb-2015
摘要: Carbonyl oxides, or Criegee intermediates, are important transient species formed in the reactions of unsaturated hydrocarbons with ozone. Although direct detection of Criegee intermediates has recently been realized, the main atmospheric sink of Criegee intermediates remains unclear. We report ultraviolet absorption spectroscopic measurements of the lifetime of the simplest Criegee intermediate, CH2OO, at various relative humidity levels up to 85% at 298 kelvin. An extremely fast decay rate of CH2OO was observed at high humidity. The observed quadratic dependence of the decay rate on water concentration implied a predominant reaction with water dimer. On the basis of the water dimer equilibrium constant, the effective rate coefficient of the CH2OO + (H2O)(2) reaction was determined to be 6.5 (+/-0.8) x 10(-12) cubic centimeters per second. This work would help modelers to better constrain the atmospheric concentrations of CH2OO.
URI: http://dx.doi.org/10.1126/science.1261549
http://hdl.handle.net/11536/124327
ISSN: 0036-8075
DOI: 10.1126/science.1261549
期刊: SCIENCE
Volume: 347
Issue: 6223
起始頁: 751
結束頁: 754
Appears in Collections:Articles