Singlet Oxygen Generation via UV-A, -B, and -C Photoexcitation of Isoprene-Oxygen (C5H8-O2) Encounter Complexes in the Gas Phase

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Singlet Oxygen Generation via UV-A, -B, and -C Photoexcitation of Isoprene-Oxygen (C₅H₈-O₂) Encounter Complexes in the Gas Phase. / Pyryaeva, Alexandra P.; Ershov, Kirill S.; Kochubei, Sergei A. и др.

в: The journal of physical chemistry. A, Том 124, № 41, 15.10.2020, стр. 8469-8477.

Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование

BibTeX

@article{1aa7ffebfba04637a90d049f01da80bd,

title = "Singlet Oxygen Generation via UV-A, -B, and -C Photoexcitation of Isoprene-Oxygen (C5H8-O2) Encounter Complexes in the Gas Phase",

abstract = "The formation of singlet oxygen 1O2 provided by the photoexcitation of the encounter complexes of isoprene with oxygen (C5H8-O2) in the gas phase within the spectral region 253.5-355 nm has been observed at the elevated pressure of oxygen. Singlet oxygen has been detected with its NIR luminescence centered near 1.27 μm. The photogeneration of 1O2 is found to be a one-photon process. In the UV-C region (253-278 nm) the quantum yield of 1O2 is measured. This yield of 1O2 is governed mainly by photoexcitation of O2 molecules to the Herzberg III (3Δu) state via enhanced absorption by C5H8-O2 collision complexes. So excited triplet O2 gives rise to singlet oxygen because of triplet-triplet annihilation in the collisions with unexcited O2 molecules. In the UV-B (308 nm) region the appearance of 1O2 is attributed to the excitation of a double spin-flip (DSF) transition in complex C5H8-O2. In the UV-A region (355 nm) besides DSF the O2-assisted T1 ← S0 excitation of isoprene to the triplet state takes place, which is a sensitizer of 1O2 formation. The contribution of the encounter complexes C5H8-O2 to the production of singlet oxygen and to the lifetime of isoprene in the Earth's troposphere are estimated.",

keywords = "MOLECULAR-OXYGEN, TRIPLET TRANSITIONS, HERZBERG PHOTOABSORPTION, ELECTRONIC-TRANSITIONS, ABSORPTION-SPECTRA, O-2, PHOTOCHEMISTRY, IRRADIATION, EXCITATION, MIXTURES",

author = "Pyryaeva, {Alexandra P.} and Ershov, {Kirill S.} and Kochubei, {Sergei A.} and Baklanov, {Alexey V.}",

year = "2020",

month = oct,

day = "15",

doi = "10.1021/acs.jpca.0c07509",

language = "English",

volume = "124",

pages = "8469--8477",

journal = "Journal of Physical Chemistry A",

issn = "1089-5639",

publisher = "American Chemical Society",

number = "41",

}

RIS

TY - JOUR

T1 - Singlet Oxygen Generation via UV-A, -B, and -C Photoexcitation of Isoprene-Oxygen (C5H8-O2) Encounter Complexes in the Gas Phase

AU - Pyryaeva, Alexandra P.

AU - Ershov, Kirill S.

AU - Kochubei, Sergei A.

AU - Baklanov, Alexey V.

PY - 2020/10/15

Y1 - 2020/10/15

N2 - The formation of singlet oxygen 1O2 provided by the photoexcitation of the encounter complexes of isoprene with oxygen (C5H8-O2) in the gas phase within the spectral region 253.5-355 nm has been observed at the elevated pressure of oxygen. Singlet oxygen has been detected with its NIR luminescence centered near 1.27 μm. The photogeneration of 1O2 is found to be a one-photon process. In the UV-C region (253-278 nm) the quantum yield of 1O2 is measured. This yield of 1O2 is governed mainly by photoexcitation of O2 molecules to the Herzberg III (3Δu) state via enhanced absorption by C5H8-O2 collision complexes. So excited triplet O2 gives rise to singlet oxygen because of triplet-triplet annihilation in the collisions with unexcited O2 molecules. In the UV-B (308 nm) region the appearance of 1O2 is attributed to the excitation of a double spin-flip (DSF) transition in complex C5H8-O2. In the UV-A region (355 nm) besides DSF the O2-assisted T1 ← S0 excitation of isoprene to the triplet state takes place, which is a sensitizer of 1O2 formation. The contribution of the encounter complexes C5H8-O2 to the production of singlet oxygen and to the lifetime of isoprene in the Earth's troposphere are estimated.

AB - The formation of singlet oxygen 1O2 provided by the photoexcitation of the encounter complexes of isoprene with oxygen (C5H8-O2) in the gas phase within the spectral region 253.5-355 nm has been observed at the elevated pressure of oxygen. Singlet oxygen has been detected with its NIR luminescence centered near 1.27 μm. The photogeneration of 1O2 is found to be a one-photon process. In the UV-C region (253-278 nm) the quantum yield of 1O2 is measured. This yield of 1O2 is governed mainly by photoexcitation of O2 molecules to the Herzberg III (3Δu) state via enhanced absorption by C5H8-O2 collision complexes. So excited triplet O2 gives rise to singlet oxygen because of triplet-triplet annihilation in the collisions with unexcited O2 molecules. In the UV-B (308 nm) region the appearance of 1O2 is attributed to the excitation of a double spin-flip (DSF) transition in complex C5H8-O2. In the UV-A region (355 nm) besides DSF the O2-assisted T1 ← S0 excitation of isoprene to the triplet state takes place, which is a sensitizer of 1O2 formation. The contribution of the encounter complexes C5H8-O2 to the production of singlet oxygen and to the lifetime of isoprene in the Earth's troposphere are estimated.

KW - MOLECULAR-OXYGEN

KW - TRIPLET TRANSITIONS

KW - HERZBERG PHOTOABSORPTION

KW - ELECTRONIC-TRANSITIONS

KW - ABSORPTION-SPECTRA

KW - O-2

KW - PHOTOCHEMISTRY

KW - IRRADIATION

KW - EXCITATION

KW - MIXTURES

UR - http://www.scopus.com/inward/record.url?scp=85093538814&partnerID=8YFLogxK

U2 - 10.1021/acs.jpca.0c07509

DO - 10.1021/acs.jpca.0c07509

M3 - Article

C2 - 32986424

AN - SCOPUS:85093538814

VL - 124

SP - 8469

EP - 8477

JO - Journal of Physical Chemistry A

JF - Journal of Physical Chemistry A

SN - 1089-5639

IS - 41

ER -

ID: 25687127