Naslov
Stacking interactions: a broader perspective

Autori
Molčanov, Krešimir ; Kojić-Prodić, Biserka

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

Izvornik
Solid State Science & Research Meeting, Book of Abstracts / Biliškov, Nikola - Zagreb : Institut Ruđer Bošković, 2019, 25-25

ISBN
978-953-7941-32-1

Skup
Solid State Science and Research Meeting

Mjesto i datum
Zagreb, Hrvatska, 27.06.2019. - 29.06.2019

Vrsta sudjelovanja
Pozvano predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
pi-interactions ; stacking ; charge density ; radicals ; quinones

Sažetak
Stacking of aromatic rings is a well-known type of intermolecular interaction. It is usually considered as rather weak (typically <1 kcal mol-1), and is assumed that it is an exclusive property of aromatic rings ; the fact that other types of planar conjugated rings also stack is usually overlooked. However, there is a growing amount of evidence that all rings stack, and that aromaticity is not a conditio sine qua non for formation of π-stacks. Stacking of planar organic radicals has been used in design of organic semiconductors and magnetic materials for more than a decade. Our detailed studies have shown that interactions between quinoid rings and semiquinone radicals are by an order of a magnitude stronger than interactions between aromatics. As a result of numerous X-ray charge density studies on different types of stacked rings, we propose a generalised model of stacking, which accounts for both aromatic and non-aromatic rings. It covers a wide range of interactions and energies ranging from weak dispersion (E ≤ 1 kcal mol-1) to non-localised two-electron multicentric covalent bonding ('pancake bonding', E ≥ 15 kcal mol-1). Thus, stacking can be compared to hydrogen and halogen bonding and can be categorised as weak, mainly dispersion (aromatic stacks) ; medium, mainly electrostatic (non-aromatic rings, such as quinones and metal-chelates) and strong, partially covalent (planar organic radicals).

Izvorni jezik
Engleski

Znanstvena područja
Kemija

POVEZANOST RADA