Laser-induced fluorescence excitation spectra of tert-butoxy and 2-butoxy radicals

Journal Article · Thu Oct 14 04:00:00 EDT 1999 · Journal of Physical Chemistry A: Molecules, Spectroscopy, Kinetics, Environment, amp General Theory

DOI:https://doi.org/10.1021/jp9918050· OSTI ID:20001148

Wang, C; Shemesh, L G; Deng, W; Lilien, M D; Dibble, T S

Laser-induced fluorescence (LIF) excitation spectra of t-C{sub 4}H{sub 9}O (tert-butoxy) and 2-C{sub 4}H{sub 9}O (2-butoxy) radicals were investigated in the wavelength range 335--400 nm. The radicals were formed by laser photolysis of the corresponding butyl nitrites at 355 nm. for tert-butoxy, 16 vibronic bands in two progressions were labeled. The dominant progression corresponds to C-O stretching mode with {nu}{prime}{sub c-o} = 521 {+-} 10 cm{sup {minus}1}. The transition organ was tentatively assigned at 25 866 cm{sup {minus}1} (386.6 nm). Numerous bands remain unassigned. The LIF excitation spectrum of 2-butoxy, consisting of 15 vibronic bands in four progressions, was observed for the first time. A C-O stretching frequency {nu}{prime}{sub c-o} = 567 {+-} 10 cm{sup {minus}1} was obtained from the dominant progression. The transition origin was tentatively assigned at 26 185 cm{sup {minus}1} (381.9nm). Three other progressions are evident, which have different vibrational band intervals: 617 {+-} 10, 590 {+-} 10, and 552 {+-} 10 cm{sup {minus}1}. Zero-pressure fluorescence lifetimes for numerous vibronic bands of tert-butoxy and 2-butoxy were determined to be about 150 and 85 ns, respectively. The spectra can be used as a convenient spectroscopic tool for kinetic studies of butoxy radicals and should provide a starting point for investigation of their excited states structure and dynamics.

• Research Organization: State Univ. of New York, Syracuse, NY (US)
• OSTI ID: 20001148
• Journal Information: Journal of Physical Chemistry A: Molecules, Spectroscopy, Kinetics, Environment, amp General Theory, Journal Name: Journal of Physical Chemistry A: Molecules, Spectroscopy, Kinetics, Environment, amp General Theory Journal Issue: 41 Vol. 103; ISSN 1089-5639; ISSN JPCAFH
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
ATMOSPHERIC CHEMISTRY
BUTOXY RADICALS
EXCITATION
FLUORESCENCE
LASERS
LIFETIME
SPECTRA