Combination Of Iodine Quadrupole Coupling And Essentially Free Methyl Internal Rotation In 3-iodotoluene

Signore, Joshua A.

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https://hdl.handle.net/2142/111266 Copy

Description

Title

Combination Of Iodine Quadrupole Coupling And Essentially Free Methyl Internal Rotation In 3-iodotoluene

Author(s)

Signore, Joshua A.

Contributor(s)

• Novick, Stewart E.
• Cooke, S. A.
• Pringle, Wallace C.
• Nguyen, Ha Vinh Lam

Issue Date

2021-06-23

Keyword(s)

Mini-symposium: Large Amplitude Motions

Abstract

Quadrupole coupling of an iodine nucleus with its coupling constants in the GHz order has always been a challenge in microwave spectroscopy. Methyl internal rotations with very low torsional barriers also often complicate the spectral analysis and modeling.\footnote{H.V.L. Nguyen and I. Kleiner, \textit{Phys. Sci. Rev.} DOI: 10.1515/psr-2020-0037, in press.} Here, we present the microwave spectrum of a molecule combining the two effects, 3-iodotoluene, observed using a Balle-Flygare Fourier transform microwave spectrometer. The A torsional state including the iodine hyperfine structure has been successfully assigned and fitted utilizing Pickett's \textit{SPFIT/SPCAT}.\footnote{H.M. Pickett, \textit{J. Mol. Spectrosc.} \textbf{148}, 371 (1991).} As expected, the assignment of E torsional state lines has been proven quite challenging due to the extremely low barrier to internal rotation in presence of the iodine hyperfine patterns. Currently, a tentative E state assignment exists and is checked by a separate fit which includes the odd power parameters D$_{a}$ and D$_{b}$ (multiplying the P$_{a}$ and P$_{b}$ operators) and their higher order parameters in the Hamiltonian. We believe that this is the first microwave report that investigates a molecular species possessing a very low barrier to internal rotation with an iodine embedded in its molecular framework. \\

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

Text

Language

eng

Permalink

http://hdl.handle.net/2142/111266

DOI

10.15278/isms.2021.WH08

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