Absolute configuration of 3-methylcyclohexanone by chiral tag rotational spectroscopy and vibrational circular dichroism

Holdren, Martin S.

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https://hdl.handle.net/2142/97108 Copy

Description

Title

Absolute configuration of 3-methylcyclohexanone by chiral tag rotational spectroscopy and vibrational circular dichroism

Author(s)

Holdren, Martin S.

Contributor(s)

• Pate, Brooks
• West, Channing
• Smart, Taylor
• Mayer, Kevin J.
• Evangelisti, Luca

Issue Date

2017-06-22

Keyword(s)

Chirality-sensitive spectroscopy

Abstract

The absolute configuration of 3-methylcyclohexanone was established by chiral tag rotational spectroscopy measurements using 3-butyn-2-ol as the tag partner. This molecule was chosen because it is a benchmark measurement for vibrational circular dichroism (VCD). A comparison of the analysis approaches of chiral tag rotational spectroscopy and VCD will be presented. One important issue in chiral analysis by both methods is the conformational flexibility of the molecule being analyzed. The analysis of conformational composition of samples will be illustrated. In this case, the high spectral resolution of molecular rotational spectroscopy and potential for spectral simplification by conformational cooling in the pulsed jet expansion are advantages for chiral tag spectroscopy. The computational chemistry requirements for the two methods will also be discussed. In this case, the need to perform conformer searches for weakly bound complexes and to perform reasonably high level quantum chemistry geometry optimizations on these complexes makes the computational time requirements less favorable for chiral tag rotational spectroscopy. Finally, the issue of reliability of the determination of the absolute configuration will be considered. In this case, rotational spectroscopy offers a “gold standard” analysis method through the determination of the $^{13}$C-subsitution structure of the complex between 3-methylcyclohexanone and an enantiopure sample of the 3-butyn-2-ol tag.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

eng

Permalink

http://hdl.handle.net/2142/97108

DOI

https://doi.org/10.15278/isms.2017.RG10

Copyright and License Information

Copyright 2017 Martin S. Holdren

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