2023-Sustainable Industrial Processing Summit
SIPS2023 Volume 8. Poeppelmeier Intl. Symp. / Solid State Chemistry
| Editors: | F. Kongoli, M. Delferro, P. S. Halasyamani, M. A. Alario-Franco, F. Marquis, A. Tressaud, H. Kageyama |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2023 |
| Pages: | 144 pages |
| ISBN: | 978-1-989820-86-5 (CD) |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
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THE CRYSTAL STRUCTURE OF CARBONIC ACID
Richard Dronskowski1;1RWTH AACHEN UNIVERSITY, 52056 Aachen, Germany;
Type of Paper: Regular
Id Paper: 260
Topic: 52
Abstract:
Ubiquitous carbonic acid, H2CO3, a key molecule in biochemistry, geochemistry, and also extraterrestrial chemistry, is synthetically known [1], also from spectroscopic studies [2], but it is often considered, even up to the present day, a somewhat mysterious “non-existing” molecule. In fact, the molecule has never been directly seen because high pressure is needed to stabilize it, as easily shown by electronic-structure theory. After an eight-years research study, the crystal structure of carbonic acid has been determined from neutron-diffraction data [3] on a deuterated sample in a specially built hybrid clamped cell [4] made from “Russian alloy”. At 1.85 GPa, D2CO3 crystallizes in the monoclinic space group P21/c with a = 5.392(2), b = 6.661(4), c = 5.690(1) Å, β = 92.66(3)°, Z = 4, with one symmetry-inequivalent anti-anti shaped D2CO3 molecule forming dimers [5], as qualitatively predicted before. Quantum chemistry from plane waves using local orbitals evidences π bonding within the CO3 molecular core, very strong hydrogen bonding between the molecules, and a massive influence of the Madelung field; phonon calculations emphasize the locality of the vibrations, being rather insensitive to the extended structure. Now that carbonic acid has been firmly established, this may be useful for other fields, for example CO2 “sequestration” and its consequences. Likewise, carbonic acid probably plays a role in our solar system, say, on outer gas planets such as Uranus or Neptune and, also, on the Jupiter moon Europa. Finally, many chemistry textbooks must be rewritten because the simplest molecule consisting of water and carbon dioxide actually exists and can be observed.
Keywords:
Advanced Characterization Techniques And Applications; Important Classes Of Materials; high pressure; neutron diffraction; density-functional theory; chemical bondingReferences:
[1] G. Gattow, U. Gerwarth, Angew. Chem. Int. Ed. Engl. 4 (1965) 149.[2] T. Loerting, C. Tautermann, R. T. Kroemer, I. Kohl, A. Hallbrucker, E. Mayer, K. R. Liedl, Angew. Chem. Int. Ed. 39 (2000) 891–894.
[3] M. Hofmann, R. Schneider, G. A. Seidl, J. Rebelo-Kornmeier, U. Garbe, R. Schneider, R. C. Wimpory, U. Wasmuth, U. Noster, Phys. B 385–386 (2006) 1035–1037.
[4] S. Benz, A. Möller, T. Marioneck, M. Hofmann, J. Brenk, R. Dronskowski, Rev. Sci. Instrum. 90 (2019) 026103.
[5] S. Benz, D. Chen, A. Möller, M. Hofmann, D. Schnieders, R. Dronskowski, Inorganics 10 (2022) 132.