INFRARED SPECTROSCOPY OF BUTYL RADICALS IN He NANODROPLETS

King, Kale E.

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https://hdl.handle.net/2142/107634 Copy

Description

Title

INFRARED SPECTROSCOPY OF BUTYL RADICALS IN He NANODROPLETS

Author(s)

King, Kale E.

Contributor(s)

Douberly, Gary E.; Lee, Yuan-Pern ; Franke, Peter R.; Pullen, Gregory T.

Issue Date

23-Jun-20

Keyword(s)

Radicals

Abstract

Butyl radicals (\textit{n-, s-, i-,} and \textit{tert}-butyl) are formed from the pyrolysis of nitrite precursors (1-pentyl nitrite, 2-methyl-butyl nitrite, 3-methyl-butyl nitrite, and 2,2-dimethyl-propyl nitrite, respectively). The radicals are doped into a beam of liquid helium droplets and probed with infrared action spectroscopy from 2700-3125 \wn, allowing for a low temperature measurement of the CH stretching region. The presence of anharmonic resonance polyads in the 2800-3000 \wn\; region complicates assignments. To facilitate spectral assignment, the anharmonic resonances are modeled with two effective Hamiltonian approaches that explicitly couple CH stretch fundamentals to HCH bend overtones and combinations: a VPT2+K normal mode model based on CCSD(T) quartic force fields and a semi-empirical local mode model. Both methods have been previously applied to the \textit{n-} and \textit{i-}propyl radicals.\footnote{ P.R. Franke, D.P. Tabor, C.P. Moradi, G.E. Douberly, J. Agarwal, H.F. Schaefer, E.L. Sibert, Infrared laser spectroscopy of the \textit{n}-propyl and \textit{i}-propyl radicals: stretch-bend Fermi coupling in the alkyl CH stretch region, J. Chem. Phys. 145 (2016) 224304.} Extension to the butyl radicals allows for examination of the transferability of the empirical local mode coupling parameters to all types of local alkyl radical environment.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

Text

Language

English

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http://hdl.handle.net/2142/107634

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