Naslov
X-ray charge density reveals fine details in π- stacks of semiquinone radicals which determine conductivity

Autori
Molčanov, Krešimir ; Jelsch, Christian ; Šantić, Ana ; Stilinović, Vladimir ; Wenger, Emmanuel ; Kojić-Prodić, Biserka

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

Izvornik
Solid State Science and Research 2017 : Book of Abstracts / Juribašić Kulscar, Marina ; Halasz, Ivan - Zagreb : Institut Ruđer Bošković, 2017, 56-56

ISBN
978-953-7941-15-4

Skup
Solid State Science and Research 2017

Mjesto i datum
Zagreb, Hrvatska, 28.06.2017. - 30.06.2017

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Domaća recenzija

Ključne riječi
semiquinone, pi-interactions, stacking, crystal engineering, X-ray charge density
(semiquinone, pi-interactions, crystal engineering, X-ray charge density)

Sažetak
Semiquinones are a class of stable organic radicals with a great potential for design of novel organic electronics and multifunctional materials. Since the radicals are planar, they typically form π-stacks, which stabilise crystal packing and determine magnetic and electrical properties of the crystals. Stronger π interactions thus imply stronger exchange interactions and lower energy barrier for electron transfer. Two types of stacks π-have been described: 1) Peierls-distorted with alternating short (< 3.1 Å) and long (> 3.35 Å) interplanar distances (i.e. comprising dimers of radicals with paired spins), which are diamagnetic and isolators and 2) stacks of equidistant radicals which are 1D antiferromagnetic and semiconductors. Despite its importance, π-stacking of planar organic radicals has been little studied from the fundamental point of view. Here we present a detailed X-ray charge density study of two types of semiquinone stacks and correlate them with magnetic and (semi)conductive properties of the crystals. As a convenient model system we chose N-methylpyridinium salt of tetrachlorosemiquinone radical anion, which forms stable, well-developed crystals and contains no heavy atoms. Two polymorphs of the studied salt are known: a diamagnetic one with Peierls-distorted stacks and an antiferromagnetic one with stacks of equidistant radicals.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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