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Ultraviolet Absorption Spectrum and Cross Sections of Vinyl [C2H3] Radical in the 225-238 nm Region



Askar Fahr, P Hassanzadeh, D B. Atkinson


The room temperature gas phase ultraviolet absorption spectrum and cross sections of vinyl [C2H3] radicals have been determined in the spectral range 225 nm-238 nm, employing cavity ring-down absorption spectroscopy. Vinyl radicals in these experiments were produced from the 193-nm excimer laser photolysis of methyl-vinyl-ketone [CH3COC2H3] and vinyl bromide [C2H3Br]. The spectra obtained from the two systems were nearly identical. The observed spectrum exhibits a relatively broad and featureless absorption with a cross section of 5.3 x 1018 cm2 molecule-1 at 230 nm. The electronic transitions in the vinyl radical have been calculated by ab initio quantum chemical methods at the CIS, EOM-CCSD, CASSCF and CASPT2 levels of theories and assign the new observed band to the highly allowed and in plane π* [2a]
Journal of Physical Chemistry


ab initio methods, cavity ring down spectroscopy, cross sections, electronic transitions, gas phase, ultraviolet absorption, Vinyl Radical


Fahr, A. , Hassanzadeh, P. and Atkinson, D. (1998), Ultraviolet Absorption Spectrum and Cross Sections of Vinyl [C<sub>2</sub>H<sub>3</sub>] Radical in the 225-238 nm Region, Journal of Physical Chemistry (Accessed April 16, 2024)
Created September 15, 1998, Updated February 17, 2017