Hysteretic Room-Temperature Magnetic Bistability of the Crystalline 4,7-Difluoro-1,3,2-Benzodithiazolyl Radical.

Autor: Makarov AY; Vorozhtsov Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, 630090, Novosibirsk, Russia., Buravlev AA; Vorozhtsov Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, 630090, Novosibirsk, Russia.; Department of Natural Sciences National Research University, Novosibirsk State University, 630090, Novosibirsk, Russia., Romanenko GV; International Tomography Center, Siberian Branch, Russian Academy of Sciences, 630090, Novosibirsk, Russia., Bogomyakov AS; International Tomography Center, Siberian Branch, Russian Academy of Sciences, 630090, Novosibirsk, Russia., Zakharov BA; Boreskov Institute of Catalysis, Siberian Branch, Russian Academy of Sciences, 630090, Novosibirsk, Russia.; Department of Natural Sciences National Research University, Novosibirsk State University, 630090, Novosibirsk, Russia., Morozov VA; International Tomography Center, Siberian Branch, Russian Academy of Sciences, 630090, Novosibirsk, Russia., Sukhikh AS; Nikolaev Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences, 630090, Novosibirsk, Russia.; Department of Physics, National Research University - Novosibirsk State University, 630090, Novosibirsk, Russia., Shundrina IK; Vorozhtsov Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, 630090, Novosibirsk, Russia., Shundrin LA; Vorozhtsov Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, 630090, Novosibirsk, Russia., Irtegova IG; Vorozhtsov Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, 630090, Novosibirsk, Russia., Cherepanova SV; Boreskov Institute of Catalysis, Siberian Branch, Russian Academy of Sciences, 630090, Novosibirsk, Russia., Bagryanskaya IY; Vorozhtsov Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, 630090, Novosibirsk, Russia., Nikulshin PV; Vorozhtsov Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, 630090, Novosibirsk, Russia.; Current address: Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, 119991, Moscow, Russia., Zibarev AV; Vorozhtsov Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, 630090, Novosibirsk, Russia.
Jazyk: angličtina
Zdroj: ChemPlusChem [Chempluschem] 2024 Jun; Vol. 89 (6), pp. e202300736. Date of Electronic Publication: 2024 Feb 26.
DOI: 10.1002/cplu.202300736
Abstrakt: The title radical R⋅, synthesized by reduction of the corresponding cation R + , is thermally stable up to ~380 K in the crystalline state under anaerobic conditions. With SQUID magnetometry, single-crystal and powder XRD, solid-state EPR and TG-DSC, reversible spin-Peierls transition between diamagnetic and paramagnetic states featuring ~10 K hysteretic loop is observed for R⋅ in the temperature range ~310-325 K; ΔH=~2.03 kJ mol -1 and ΔS=~6.23 J mol -1 K -1 . The transition is accompanied by mechanical movement of the crystals, i. e., by thermosalient behavior. The low-temperature diamagnetic P-1 polymorph of R⋅ consists of R⋅ 2 π-dimers arranged in (…R⋅ 2 …) n π-stacks; whereas the high-temperature paramagnetic P2 1 /c polymorph, of uniform (…R⋅…) n π-stacks. With the XRD geometries, CASSCF and broken-symmetry DFT jointly suggest strong antiferromagnetic (AF) interactions within R⋅ 2 and weak between R⋅ 2 for the (…R⋅ 2 …) n stacks; and moderate AF interactions between R⋅ for the (…R⋅…) n stacks. The fully hydrocarbon archetype of R⋅ does not reveal the aforementioned properties. Thus, the fluorinated 1,3,2-benzodithiazolyls pave a new pathway in the design and synthesis of metal-less magnetically-bistable materials.
(© 2024 Wiley-VCH GmbH.)
Databáze: MEDLINE
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