Abstract: The recognition properties of cucurbit[8]uril (CB8) toward nitronyl nitroxide 2-(2-benzimidazolyl)-4,4,5,5-tetramethylimidazolidinyl-3-oxide-1-oxy (1) and its hydrochloride have been investigated. 1⋅HCl led to 1:1 inclusion complex [1⋅HCl@CB8], which was characterized both in solution and by single-crystal X-ray diffraction. In this compound only the tetramethylimidazolidinyl fragment is included in the host. The magnetic behavior of the complex corresponds to a Curie law with a large separation of the spin carriers in the solid. In contrast, an insoluble species exhibiting ferromagnetic behavior is formed when pure 1 reacts with acid-free CB8. The formula [(1)2@(CB8)3], in which two radical guests are arranged in such a way that the phenyl groups of the benzimidazolyl substituents are both stacked into one CB8 and the tetramethyl fragments are each capped by a terminal macrocycle, is proposed, in agreement with microanalysis, spectrophotometric, EPR, and magnetic measurements. According to McConnell’s rules, the alternating spin densities within the stacked aromatic fragments result in a ferromagnetic interaction (J=+2.3 cm−1, H=−2 JS1S2) and a triplet ground spin state for the inclusion complex.

Cite: Peresypkina E.V. , Fedin V.P. , Maurel V. , Grand A. , Rey P. , Vostrikova K.E.
Inclusion of a Nitronyl Nitroxyl Radical and Its Hydrochloride in Cucurbit[8]uril
Chemistry: A European Journal. 2010. V.16. N41. P.12481-12487. DOI: 10.1002/chem.201001194 Scopus OpenAlex

Identifiers:

Scopus:	2-s2.0-78249240055
OpenAlex:	W2047527741

Citing:

DB	Citing
Scopus	16
OpenAlex	16

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