The ethanol-CO2 dimer is an electron donor-acceptor complex

McGuire, Brett A.

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https://hdl.handle.net/2142/97189 Copy

Description

Title

The ethanol-CO2 dimer is an electron donor-acceptor complex

Author(s)

McGuire, Brett A.

Contributor(s)

• McCarthy, Michael C.
• Martin-Drumel, Marie-Aline

Issue Date

2017-06-22

Keyword(s)

Clusters/complexes

Abstract

Supercritical (sc) CO$_2$ is a common industrial solvent for the extraction of caffeine, nicotine, petrochemicals, and natural products. The ability of apolar scCO$_2$ to dissolve polar solutes is greatly enhanced by the addition of a polar co-solvent, often methanol or ethanol. Experimental and theoretical work show that methanol interactions in scCO$_2$ are predominantly hydrogen bonding, while the gas-phase complex is an electron donor-acceptor (EDA) configuration. Ethanol, meanwhile, is predicted to form EDA complexes both in scCO$_2$ and in the gas phase, but there have been no experimental measurements to support this conclusion. Here, we report a combined chirped-pulse and cavity FTMW study of the ethanol-CO$_2$ complex. Comparison with theory indicates the EDA complex is dominant under our experimental conditions. We confirm the structure with isotopic substitution, and derive a semi-experimental equilibrium structure. Our results are consistent with theoretical predictions that the linearity of the CO$_2$ subgroup is broken by the complexation interaction.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

eng

Permalink

http://hdl.handle.net/2142/97189

DOI

https://doi.org/10.15278/isms.2017.RH06

Copyright and License Information

Copyright 2017 Brett A. McGuire

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