Chirality Recognition In The Ternary Aggregates Of Propylene Oxide: Experimentally Guided Theoretical Conformational Searches

Xie, Fan

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https://hdl.handle.net/2142/111576 Copy

Description

Title

Chirality Recognition In The Ternary Aggregates Of Propylene Oxide: Experimentally Guided Theoretical Conformational Searches

Author(s)

Xie, Fan

Contributor(s)

• Xu, Yunjie
• Barone, Vincenzo
• Jäger, Wolfgang
• Hazrah, Arsh Singh
• Fusè, Marco

Issue Date

2021-06-25

Keyword(s)

Chirality and stereochemistry

Abstract

Propylene oxide (PO), a simple chiral cyclic ether, has served as a valuable prototype molecule for the theoretical development of chiroptical activities$^{1}$ and for rotational spectroscopic studies of chirality recognition. Although a study of the PO dimer was completed more than ten years ago where six homo- and heterochiral structures were identified experimentally$^{2}$, no similar studies of larger chiral aggregates such as a PO trimer have been reported so far. Aided with the recent development in chirped pulse Fourier transform microwave techniques$^{3}$ and in meta-dynamics conformational search algorithms$^{4}$, we have explored the conformational space of the PO trimer. Several hundred possible PO trimer structures were predicted the first two most stable homochiral trimers were assigned. The number of possible conformers of the heterochiral PO trimer predicted is about three times of the homochiral trimer. Even so, no match could be made for the heterochiral trimer conformers detected, despite additional exhausted conformational searches. By studying all monosubstituted 13C isotopologues of the most stable homochiral and heterochiral PO trimer in natural abundance, we experimentally determined their C atom backbone structures. Guided with this information, additional PO trimer structures were calculated which match the observed rotational constants and dipole moments. The study showcases the power of rotational spectroscopic experiments and highlights the necessity of intensive interplay between experiment and theory in dealing with large aggregates. 1.R. W. Kawiecki, F. J. Devlin, P. J. Stephens, R. D. Amos, J. Phys. Chem. 1991, 95, 9817. 2.Z. Su, N. Borho, Y. Xu. J. Am. Chem. Soc. 2006, 128, 51. 3.G. Barratt Park, and Robert W. Field, J. Chem. Phys. 2016, 144, 20090. 4.P. Pracht, F. Bohle and S. Grimme, Phys. Chem. Chem. Phys., 2020.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

Text

Language

eng

Permalink

http://hdl.handle.net/2142/111576

DOI

10.15278/isms.2021.FM02

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