The UV absorption spectrum of the simplest Criegee intermediate CH 2
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چکیده
Ozonolysis is a major removal mechanism in the troposphere for unsaturated hydrocarbons which are emitted in large quantities from both natural and human sources. Now it is generally accepted that ozonolysis of alkenes proceeds via Criegee intermediates, highly reactive species postulated in 1949 by Rudolf Criegee. In the troposphere, Criegee intermediates are involved in several important atmospheric reactions, including reactions with SO2 and NO2, 4–7 or can be photolyzed by near UV light, as shown for CH2OO in (R1)–(R4). C2H4 + O3 CH2OO + H2CO (R1)
منابع مشابه
UV absorption spectrum of the C2 Criegee intermediate CH3CHOO.
The UV spectrum of CH3CHOO was measured by transient absorption in a flow cell at 295 K. The absolute absorption cross sections of CH3CHOO were measured by laser depletion in a molecular beam to be (1.06 ± 0.09) × 10(-17) cm(2) molecule(-1) at 308 nm and (9.7 ± 0.6) × 10(-18) cm(2) molecule(-1) at 352 nm. After scaling the UV spectrum of CH3CHOO to the absolute cross section at 308 nm, the peak...
متن کاملThe UV absorption spectrum of the simplest Criegee intermediate CH2OO.
SO2 scavenging and self-reaction of CH2OO were utilized for the decay of CH2OO to extract the absorption spectrum of CH2OO under bulk conditions. Absolute absorption cross sections of CH2OO at 308.4 and 351.8 nm were obtained from laser-depletion measurements in a jet-cooled molecular beam. The peak cross section is (1.23 ± 0.18) × 10(-17) cm(2) at 340 nm.
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