Pancake-Bonding of Semiquinone Radicals under Variable Temperature and Pressure Conditions Full article
| Journal |
Acta Crystallographica Section B: Structural Science, Crystal Engineering and Materials
ISSN: 2052-5192 , E-ISSN: 2052-5206 |
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| Output data | Year: 2020, Volume: B76, Number: 2, Pages: 285-291 Pages count : 7 DOI: 10.1107/s2052520620002772 | ||||||
| Tags | multicentric two-electron bonding; pancake bonding; semiquinone radicals; high pressure; low temperature | ||||||
| Authors |
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| Affiliations |
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Funding (2)
| 1 | Ministry of Science and Higher Education of the Russian Federation | 0239-2019-0003 |
| 2 | Ministry of Science and Education of the Croatia | IP-2019-04-4674 |
Abstract:
The effects of temperature (100–370 K) and pressure (0–6 GPa) on the non-localized two-electron multicentric covalent bonds (`pancake bonding') in closely bound radical dimers were studied using single-crystal X-ray diffraction on a 4-cyano-N-methylpyridinium salt of 5,6-dichloro-2,3-dicyanosemiquinone radical anion (DDQ) as the sample compound. On cooling, the anisotropic structural compression was accompanied by continuous changes in molecular stacking; the discontinuities in the changes in volume and b and c cell parameters suggest that a phase transition occurs between 210 and 240 K. At a pressure of 2.55 GPa, distances between radical dimers shortened to 2.9 Å, which corresponds to distances observed in extended π-bonded polymers. Increasing pressure further to 6 GPa reduced the interplanar separation of the radicals to 2.75 Å. This may indicate that the covalent component of the interaction significantly increased, in accordance with the results of DFT calculations reported elsewhere [Molčanov et al. (2019), Cryst. Growth Des. 19, 391–402].
Cite:
Bogdanov N.E.
, Milašinović V.
, Zakharov B.A.
, Boldyreva E.V.
, Molčanov K.
Pancake-Bonding of Semiquinone Radicals under Variable Temperature and Pressure Conditions
Acta Crystallographica Section B: Structural Science, Crystal Engineering and Materials. 2020. V.B76. N2. P.285-291. DOI: 10.1107/s2052520620002772 WOS Scopus РИНЦ AN PMID OpenAlex
Pancake-Bonding of Semiquinone Radicals under Variable Temperature and Pressure Conditions
Acta Crystallographica Section B: Structural Science, Crystal Engineering and Materials. 2020. V.B76. N2. P.285-291. DOI: 10.1107/s2052520620002772 WOS Scopus РИНЦ AN PMID OpenAlex
Dates:
| Submitted: | Jan 3, 2020 |
| Accepted: | Feb 27, 2020 |
| Published online: | Mar 24, 2020 |
| Published print: | Apr 1, 2020 |
Identifiers:
| Web of science: | WOS:000525346200014 |
| Scopus: | 2-s2.0-85083077991 |
| Elibrary: | 43269355 |
| Chemical Abstracts: | 2020:648283 |
| PMID: | 32831231 |
| OpenAlex: | W3013293632 |