title: UV absorption spectrum of the C2 Criegee intermediate CH3CHOO.
abstract: 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 UV cross section is (1.27 ± 0.11) × 10(-17) cm(2) molecule(-1) at 328 nm. Compared to the simplest Criegee intermediate CH2OO, the UV absorption band of CH3CHOO is similar in intensity but blue shifted by 14 nm, resulting in a 20% slower photolysis rate estimated for CH3CHOO in the atmosphere.
authors.affiliation: Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, USA.
authors.forename: Mica C
authors.initials: MC
authors.lastname: Smith
authors.affiliation: Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan.
authors.forename: Wei-Lun
authors.initials: WL
authors.lastname: Ting
authors.affiliation: Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan.
authors.forename: Chun-Hung
authors.initials: CH
authors.lastname: Chang
authors.affiliation: Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan.
authors.forename: Kaito
authors.initials: K
authors.lastname: Takahashi
authors.affiliation: Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, USA.
authors.forename: Kristie A
authors.initials: KA
authors.lastname: Boering
authors.affiliation: Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan.
authors.forename: Jim Jr-Min
authors.initials: JJ
authors.lastname: Lin