Naslov
Multicentre bonding in dimers of tetracyanoethylene (TCNE) radical anions

Autori
Milašinović, Valentina ; Molčanov, Krešimir ; Štrbac, Petar

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
28th Croatian-Slovenian Crystallographic Meeting: Book of Abstracts / - , 2022, 70-70

Skup
28th Croatian-Slovenian Crystallographic Meeting

Mjesto i datum
Poreč, Hrvatska, 07.09.2022. - 11.09.2022

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Recenziran

Ključne riječi
multicentre bonding ; charge density ; TCNE

Sažetak
π-stacking interactions are responsible for unique properties of organic materials. Stacking of planar organic radicals involves some of the closest interplanar and intermolecular C–C contacts, of ca. 2.9 Å. [1] Quantum chemical models indicate a considerable covalent component in the total interaction, and this type of weak multicentric covalent bonding has been dubbed 'pancake bonding'. The strongest interaction of this type is found in pancake bonded dimers of radicals, and its energy can exceed 15 kcal mol-1. [2] The simplest and also one of the most thoroughly studied case of pancake bonding is two-electron four-centre covalent bond between tetracyanoethylene (TCNE−) radicals. [3] The π-bonded tetracyanoethylene dimer has been investigated for the first time by the experimental X-ray charge density. This system involves two-electron four-centre covalent bonding which is between localised, single bonds and pancake bonding, and this study will thus serve as a standard for comparison with other types of multicentre bonding. A detailed X-ray charge density study of TCNE radicals with a short separation distance of 2.81 Å revealed two symmetry-independent bonding critical points (3, −1) between the TCNE− radical rings with maximum electron density of 0.17 e Å−3, and one ring critical point (3, +1), showed in figure 1.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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