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Updated: Jul 25, 2025
08:12
A Two-Step Protocol for Umpolung Functionalization of Ketones Via Enolonium Species
Published on: August 16, 2018
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Improved semi-experimental equilibrium structure and high-level theoretical structures of ketene
Houston H Smith1, Brian J Esselman1, Samuel A Wood1
1Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
The Journal of Chemical Physics
|June 23, 2023
Summary
High-precision millimeter-wave spectroscopy of ketene (H2C=C=O) and its isotopologues yielded a new semi-experimental structure. This accurate molecular structure determination advances our understanding of ketene
Area of Science:
- Molecular Spectroscopy
- Quantum Chemistry
- Chemical Physics
Background:
- Ketene (H2C=C=O) is a fundamental organic molecule with unique chemical properties.
- Precise molecular structures are crucial for understanding chemical bonding and reactivity.
- Previous structural determinations of ketene had limitations in accuracy and precision.
Purpose of the Study:
- To determine a highly accurate and precise semi-experimental (reSE) molecular structure of ketene.
- To utilize advanced millimeter-wave spectroscopy and high-level computational methods.
- To investigate the structural parameters of ketene and its isotopologues.
Main Methods:
- Collected and analyzed millimeter-wave rotational spectra of ketene and five deuteriated isotopologues (130–750 GHz).
- Employed a sextic, S-reduced Hamiltonian in the Ir representation for spectral analysis.
- Determined the reSE structure using experimental rotational constants and computed vibration-rotation interaction and electron-mass distribution corrections from coupled-cluster calculations [CCSD(T)/cc-pCVTZ].
Main Results:
- Obtained highly precise spectroscopic constants for ketene and its isotopologues.
- Established a new, highly accurate reSE structure for ketene from 32 independent moments of inertia.
- Achieved small uncertainties (≤0.0007 Å for bond distances, 0.014° for angle) in the reSE parameters.
Conclusions:
- The determined reSE structure of ketene shows excellent agreement with high-level theoretical predictions ('best theoretical estimate' values).
- The study highlights the power of combining high-resolution spectroscopy with advanced computational chemistry for accurate molecular structure determination.
- The findings provide a benchmark for theoretical models and contribute to a deeper understanding of ketene's electronic and geometric properties.
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