CH2OO Criegee intermediate UV absorption cross-sections and kinetics of CH2OO + CH2OO and CH2OO + I as a function of pressure

被引：29

作者：

Mir, Zara S. ^{[1
]}

Lewis, Thomas R. ^{[1
]}

Onel, Lavinia ^{[1
]}

Blitz, Mark A. ^{[1
,2
]}

Seakins, Paul W. ^{[1
]}

Stone, Daniel ^{[1
]}

机构：

[1] Univ Leeds, Sch Chem, Leeds, W Yorkshire, England

[2] Univ Leeds, Natl Ctr Atmospher Sci, Leeds, W Yorkshire, England

来源：

PHYSICAL CHEMISTRY CHEMICAL PHYSICS | 2020年 / 22卷 / 17期

基金：

英国自然环境研究理事会;

关键词：

CONFORMER-DEPENDENT REACTIVITY; GAS-PHASE OZONOLYSIS; TEMPERATURE-DEPENDENCE; ATMOSPHERIC CHEMISTRY; RATE CONSTANTS; SELF-REACTION; SPECTRUM; OH; RADICALS; YIELDS;

D O I：

10.1039/d0cp00988a

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The UV absorption cross-sections of the Criegee intermediate CH2OO, and kinetics of the CH2OO self-reaction and the reaction of CH2OO with I are reported as a function of pressure at 298 K. Measurements were made using pulsed laser flash photolysis of CH2I2/O-2/N-2 gas mixtures coupled with time-resolved broadband UV absorption spectroscopy at pressures between 6 and 300 Torr. Results give a peak absorption cross-section of (1.37 +/- 0.29) x 10(-17) cm(2) at similar to 340 nm and a rate coefficient for the CH2OO self-reaction of (8.0 +/- 1.1) x 10(-11) cm(3) s(-1), with no significant pressure dependence of the absorption cross-sections or the self-reaction kinetics over the range investigated. The rate coefficient for the reaction between CH2OO and I demonstrates pressure dependence over the range investigated, with a Lindemann fit giving k(0) = (4.4 +/- 1.0) x 10(-29) cm(6) s(-1) and k(infinity) = (6.7 +/- 0.6) x 10(-11) cm(3) s(-1). The origins of IO in the system have been investigated, the implications of which are discussed.

引用

页码：9448 / 9459

页数：12

共 56 条

[1] The reaction of formaldehyde carbonyl oxide with the methyl peroxy radical and its relevance in the chemistry of the atmosphere [J].