Absorption spectra of contact-charge-transfer bans and photochemical reactions of simple alkenes in the cryogenic oxygen matrix

Journal Article · Thu Mar 12 04:00:00 EST 1987 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100290a015· OSTI ID:6807395

Hashimoto, S; Akimoto, H

The UV-vis absorption spectra and photochemistry of alkene-oxygen pairs in solid oxygen at 10 K have been studied. The contact-charge-transfer (CCT) bands well separated from the intrinsic absorption bands of isolated alkenes were recorded with the maxima at 218, 243, 234, 235, 263, and 287 nm for propene, 2-methylpropene (MP), cis-2-butene (CB), trans-2-butene (TB), 2-methyl-2-butene (MB), and 2,3-dimethyl-2-butene (DMB), respectively. The vertical transition energy correlated linearly with the ionization potential of the alkenes. Photochemical reaction products in the excitation within the CCT bands were studied by using FTIR. The reaction in the ion pair state can be classified into the following four pathways: (i) photooxygenation to given an oxygen adduct, which is observed only for DMB; (ii) cis-trans isomerization, which is the major reaction path for CB and TB, suggesting the crossing to the alkene triplet state; (iii) double-bond scission to give two corresponding carbonyl compounds, which is observed for all alkenes studied with energy threshold higher than the photooxygenation and cis-trans isomerization; (iv) formation of CO/sub 2/, CO, and O/sub 3/ which occurs at still shorter wavelength than the double-bond scission. In the case of ethene and propene, HO/sub 2/ was also produced. Relevance of the present results to those in the CCT photochemistry in the oxygen-saturated organic liquid and on the semiconductor surfaces has been discussed.

• Research Organization: National Institute for Environmental Studies, Ibaraki, Japan
• OSTI ID: 6807395
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 91:6; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400500* -- Photochemistry
500100 -- Environment
Atmospheric-- Basic Studies-- (-1989)
54 ENVIRONMENTAL SCIENCES
ABSORPTION SPECTROSCOPY
ALKENES
BUTENES
CHEMICAL REACTIONS
CHEMISTRY
DATA
ELEMENTS
EXPERIMENTAL DATA
HYDROCARBONS
INFORMATION
INFRARED SPECTRA
IONIZATION POTENTIAL
MATRIX ISOLATION
NONMETALS
NUMERICAL DATA
ORGANIC COMPOUNDS
OXYGEN
PHOTOCHEMICAL REACTIONS
PHOTOCHEMISTRY
PROPYLENE
SPECTRA
SPECTROSCOPY
ULTRALOW TEMPERATURE
ULTRAVIOLET SPECTRA
VISIBLE SPECTRA