Abstract: A series of new salts with paramagnetic cations – N-alkylpyridinium nitrates (NNp/mR)NO3 (where NNp/mR is 2-(4-N-R-pyridinium)- and 2-(3-N-R-pyridinium)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazo-1-oxyl-3-oxide; R = Me, Et) – were synthesized and structurally and magnetochemically characterized. All compounds – (NNpMe)NO3, (NNmMe)NO3•1/3MeCN•1/6H2O and (NNpEt)NO3 – were obtained by the interaction of iodides (NNp/mR)I with AgNO3, including a double complex salt of unusual composition (NNmEt)6[Ag(NO3)3](NO3)4. It is shown that cation-anionic interactions are decisive, facilitating the formation of cation-radical layers with short distances between paramagnetic fragments. The practically constant values of the effective magnetic moment for all the studied compounds in the temperature range 50–300 K are close to 1.73 μB. Quantum-chemical calculations have shown that such values, corresponding to the theoretical value for the monoradical, are associated with a combination of ferro- and antiferromagnetic exchange interactions between paramagnetic centers in numerous exchange channels. In this case, the contribution to the exchange energy is made by interactions not only between nitroxyl groups, but also between pyridine cycles.

Cite: Fokin S. , Tolstikov S. , Chernavin P. , Bogomyakov A. , Romanenko G.
Structure and magnetic properties of spin-labeled N-alkyl-pyridinium nitrates
Polyhedron. 2025. V.281. 117728 :1-7. DOI: 10.1016/j.poly.2025.117728 WOS Scopus

Dates:

Published print:

Nov 1, 2025

Identifiers:

Web of science:	WOS:001584100300001
Scopus:	2-s2.0-105012972068

Citing: Пока нет цитирований

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