Naslov
Temperature induced magnetic bistability in a crystal of tetrachlorosemiquinone anion radical

Autori
Molčanov, Krešimir ; Kojić-Prodić, Biserka ; Babić, Darko ; Pajić, Damir ; Novosel, Nikolina ; Zadro, Krešo

Izvornik
Crystengcomm (1466-8033) 14 (2012); 7958-7964

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
semiquinone radical anion; phase transition; reversible; spin-Peierls transition; spin coupling; antiferromagnetism; paramagnetism; crystal engineering; π–stacking

Sažetak
The anion radicals with nonaromatic π–systems, such as semiquinones, are interesting in the design of functional materials. Magnetic properties of solvates of alkali salts of tetrachlorosemiquinone (chloranil) radical anion are tuned by crystal engineering using different solvents (2-butanone and acetonitrile) and/or cations (potassium and ammonium) in crystals. The structural and magnetic characteristics of two salts were studied by variable-temperature single crystal X-ray diffraction and magnetic susceptibility measurements. DFT and CAS-MP2 calculations were used to correlate magnetic and structural properties of radical anions. The solid-state structure of potassium tetrachlorosemiquinone 2-butanone solvate, influenced by temperature, switches between a paramagnetic-like monomeric radical form at high temperature (200 K) and diamagnetic dimeric one at low temperature (100 K). The reversible transition is controlled by solvent and cation types which affect intrastack distance and magnetic properties.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Kemija

POVEZANOST RADA