Synthesis and study of CuII complex with nitroxide, a jumping crystal analog

R. Z. Sagdeev, S. E. Tolstikov, S. V. Fokin, I. V. Obsharova, S. V. Tumanov, S. L. Veber, G. V. Romanenko, A. S. Bogomyakov, M. V. Fedin, E. V. Tretyakov, M. Halcrow, V. I. Ovcharenko

Результат исследования: Научные публикации в периодических изданияхстатья

1 Цитирования (Scopus)

Аннотация

We synthesized 1-ethylimidazolyl-substituted nitronyl nitroxides, i.e., 2-(1-ethylimidazol-4-yl)- (L4Et) and 2-(1-ethylimidazol-5-yl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole 3-oxide-1-oxyl (L5Et). The stable radical L5Et is an ethyl analog of 2-(1-methylimidazol-5-yl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole 3-oxide-1-oxyl (L5Me) described earlier, the reaction of which with Cu(hfac)2 (hfac is 1,1,1,5,5,5-hexafluoropentane-2,4-dionate) leads to the formation of the [Cu(hfac)2(L5Me)2] jumping crystals. The reaction of Cu(hfac)2 with L5Et with reagent ratios 1: 2 and 1: 1 yields heterospin complexes [Cu(hfac)2(L5Et)2] and [Cu(hfac)2L5Et]2, respectively. X-ray diffraction study of the mononuclear complex [Cu(hfac)2(L5Et)2] determined that the compound has a packing similar to that of jumping crystals studied earlier, with the only difference being that the O..O contacts between neigh- boring nitroxide groups were found to be 0.3—0.5 Å longer than in [Cu(hfac)2(L5Me)2]. As a result of the lengthening of these contacts, [Cu(hfac)2(L5Et)2] crystals lack chemomechanical activi- ty. We found that when cooling crystals of binuclear complex [Cu(hfac)2L5Et]2 below 50 K, the antiferromagnetic exchange between unpaired electrons of the >N—•O groups of neighboring molecules leads to the full spin-pairing of the nitroxides, with only the Cu2+ ions contributing to the residual paramagnetism of the compound.

Язык оригиналаанглийский
Страницы (с-по)222-230
Число страниц9
ЖурналRussian Chemical Bulletin
Том66
Номер выпуска2
DOI
СостояниеОпубликовано - 1 фев 2017

Fingerprint Подробные сведения о темах исследования «Synthesis and study of Cu<sup>II</sup> complex with nitroxide, a jumping crystal analog». Вместе они формируют уникальный семантический отпечаток (fingerprint).

Цитировать