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Pregled bibliografske jedinice broj: 782464

Fine-tuning of magnetic properties in semiconductive organic salts of semiquinone radical


Molčanov, Krešimir; Stilinović, Vladimir; Maltar-Strmečki, Nadica; Šantić, Ana; Kojić-Prodić, Biserka; Pajić, Damir; Jelsch, Christian; Wenger, Emmanuel
Fine-tuning of magnetic properties in semiconductive organic salts of semiquinone radical // 13th YoungChem Book of Abstracts / Brzozka, Zbigniew (ur.).
Varšava: Warsaw University of Technology, 2015. str. 64-64 (predavanje, međunarodna recenzija, sažetak, znanstveni)


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Naslov
Fine-tuning of magnetic properties in semiconductive organic salts of semiquinone radical

Autori
Molčanov, Krešimir ; Stilinović, Vladimir ; Maltar-Strmečki, Nadica ; Šantić, Ana ; Kojić-Prodić, Biserka ; Pajić, Damir ; Jelsch, Christian ; Wenger, Emmanuel

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

Izvornik
13th YoungChem Book of Abstracts / Brzozka, Zbigniew - Varšava : Warsaw University of Technology, 2015, 64-64

ISBN
978-83-61037-28-6

Skup
13th International Congress of Young Chemists

Mjesto i datum
Krakow, Poljska, 07-11.10.2015

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
semiquinone radical ; magnetic properties ; crystal structure ; conductivity

Sažetak
Semiquinones are a class of stable organic radical anions ; especially stable are ones with four electronegative substituents, which enhance delocalisation of the unpaired electrons. Therefore, they are potential candidates for design of functional materials with fine-tuned magnetic properties. Semiquinoid anions in crystals are usually stacked by π-interactions, and their magnetic properties depend on their interplanar distance. Most often, the radicals form closely bound dimers with coupled spins [1, 2], which result in diamagnetic properties. However, in smartly designed crystals the distance can be increased, so stacks with equidistant rings will appear, which may be antiferromagnetic [3] or paramagnetic. Therefore, we varied substituents on the semiquinone ring - tetrachloro- (CA), tetrabromo- (BA) and 2, 3-dicyano-5, 6-dichlorosemiquinone (DDQ) were used as anions ; aromatic, approximately planar organic cations (pyridinium, N-methylpyridinium and diquat) were used to check for possible π-interactions between cations and anions. The goal of our research was design novel stable (in air, at room temperature) semiquinone systems with fine-tuned magnetic properties by crystal engineering: we varied size of substituents on the quinoid ring and aromatic organic cations. A combination of crystallographic, magnetic (EPR, SQUID), electrical (impedance spectroscopy) and thermal (TG/DTA, DSC) methods was used to obtain data on stability and magnetic properties of the crystalline compounds. To gain further insight into spin coupling/decoupling, impedance spectroscopy was used to measure band gap between radicals (or dimers of radicals) ; measurement was done on single crystals with electrical contacts applied in the direction of stacking. A pair of analogous salts, N-MePy∙CA and N-MePy∙BA is especially interesting, and be described in detail. In triclinic polymorphh of CA salt closely bound radical dimers occur, similar to previously known alkali salts of semiquinones [1, 2], and the crystals are diamagnetic due to spin pairing. In its triclinic polymorph and isostructural BA salt radicals are equdistant leading to different spin ordering, similar to high-temperature polymorph of K∙CA∙MeCOEt [3]. All crystals were found to be good semiconductors and stable in air at room temperature. [1] K. Molčanov, B. Kojić-Prodić, D. Babić, D. Žilić, B. Rakvin, CrystEngComm, 13 (2011), 5170-5178 ; [2] K. Molčanov, D. Babić, B. Kojić-Prodić, J. Stare, N. Maltar-Strmečki, L. Androš, Acta Crystallogr. B, 70 (2014), 181-190 ; [3] K. Molčanov, B. Kojić-Prodić, D. Babić, D. Pajić, N. Novosel, K. Zadro, CrystEngComm, 14 (2012), 7958-7964.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Kemija

Napomena
Djelomično financirala Zaklada HAZU (za 2014. godinu) i hrvatsko-francuska bilaterala - Cogito.



POVEZANOST RADA


Projekti:
IP-2013-11-1108 - Karakterizacija niskotemperaturne molekulske dinamike sustava s neuređenom rešetkom metodom ESR (DESiRe) (Ilakovac Kveder, Marina, HRZZ - 2013-11) ( POIROT)
HRZZ-IP-2014-09-4079 - Novi metal-organsi sustavi s oksalatnim i kinoidnim ligandima s podešenim svojstvima pogodnim za primjenu (NMOSBOQLWTPSFP) (Molčanov, Krešimir, HRZZ - 2014-09) ( POIROT)

Ustanove:
Institut "Ruđer Bošković", Zagreb,
Prirodoslovno-matematički fakultet, Zagreb

Citiraj ovu publikaciju

Molčanov, Krešimir; Stilinović, Vladimir; Maltar-Strmečki, Nadica; Šantić, Ana; Kojić-Prodić, Biserka; Pajić, Damir; Jelsch, Christian; Wenger, Emmanuel
Fine-tuning of magnetic properties in semiconductive organic salts of semiquinone radical // 13th YoungChem Book of Abstracts / Brzozka, Zbigniew (ur.).
Varšava: Warsaw University of Technology, 2015. str. 64-64 (predavanje, međunarodna recenzija, sažetak, znanstveni)
Molčanov, K., Stilinović, V., Maltar-Strmečki, N., Šantić, A., Kojić-Prodić, B., Pajić, D., Jelsch, C. & Wenger, E. (2015) Fine-tuning of magnetic properties in semiconductive organic salts of semiquinone radical. U: Brzozka, Z. (ur.)13th YoungChem Book of Abstracts.
@article{article, editor = {Brzozka, Z.}, year = {2015}, pages = {64-64}, keywords = {semiquinone radical, magnetic properties, crystal structure, conductivity}, isbn = {978-83-61037-28-6}, title = {Fine-tuning of magnetic properties in semiconductive organic salts of semiquinone radical}, keyword = {semiquinone radical, magnetic properties, crystal structure, conductivity}, publisher = {Warsaw University of Technology}, publisherplace = {Krakow, Poljska} }
@article{article, editor = {Brzozka, Z.}, year = {2015}, pages = {64-64}, keywords = {semiquinone radical, magnetic properties, crystal structure, conductivity}, isbn = {978-83-61037-28-6}, title = {Fine-tuning of magnetic properties in semiconductive organic salts of semiquinone radical}, keyword = {semiquinone radical, magnetic properties, crystal structure, conductivity}, publisher = {Warsaw University of Technology}, publisherplace = {Krakow, Poljska} }




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