Abstract
Dispersed laser-induced fluorescence of the à 2 A 2 →X̃ 2 B 1 transition of OClO in solid Ne in the spectral range 500-770 nm was recorded when the origin at 20991cm -1 was excited. Progressions with spacings near 939 and 446cm -1 are associated with vibrational modes ν 1 and ν 2 of the X̃ state. A simultaneous fit of both modes yields ω 1 ″ =957.1±1.4, ω 2 ″ =452.6±0.4, x 11 ″ =4.47±0.04, x 22 ″ =0.54±0.05, and x 12 ″ =4.00±0.05cm -1 . When the 1 0 1 line of the Ã-X̃ system at 21699cm -1 was excited, vibrationally unrelaxed emission was observed in the spectral region 480-600 nm. Excitation of the 2 0 1 line at 21284cm -1 generated weak vibrationally unrelaxed progressions. The visible absorption spectrum of OClO in solid Ne in the region 415-488 nm was recorded with a Fourier-transform spectrometer, yielding ν 00 =20991.3, ν 1 ′ =707.9, ν 2 ′ =292.5, and 2ν 3 ′ =887.6cm -1 for the à state. Simultaneous fits considering either only ν 1 and ν 2 modes or all three modes yield corresponding spectral parameters. Similar experiments were performed with OClO in solid Ar and Kr. Pronounced increases in ν 1 ′ (716.0cm -1 in Ar and 712.5cm -1 in Kr) and ν 2 ′ (302.3cm -1 in Ar and 303.0cm -1 in Kr) and a decrease in ν 00 (188cm -1 and 331cm -1 red-shifted, respectively) from that in the gas phase indicate substantial perturbation of the à state in solid Ar and Kr. An absorption continuum underlying the Ã-X̃ system is attributed to absorption to the 1̃ 2 A 1 state above the predissociation barrier. The phonon interaction increases and the threshold of the continuum decreases as the matrix host is altered from Ne to Ar to Kr.
Original language | English |
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Pages (from-to) | 978-987 |
Number of pages | 10 |
Journal | Journal of Chemical Physics |
Volume | 109 |
Issue number | 3 |
DOIs | |
State | Published - 1 Dec 1998 |