2D and 3D Cu(hfac)2 Complexes with Nitronyl Nitroxide Biradicals

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• 作者：Eugene Tretyakov ; Sergei Fokin ; Galina Romanenko ; Vladimir Ikorskii ; Sergei Vasilevsky ; and Victor Ovcharenko
• 刊名：Inorganic Chemistry
• 出版年：2006
• 出版时间：May 1, 2006
• 年：2006
• 卷：45
• 期：9
• 页码：3671 - 3678
• 全文大小：348K
• 年卷期：v.45,no.9(May 1, 2006)
• ISSN：1520-510X

文摘

Reactions between Cu(hfac)₂ and nitronyl nitroxide biradicals 1,4-bis[4-(4,4,5,5-tetramethyl-3-oxide-1-oxyl-4,5-dihydro-1H-imidazol-2-yl)pyrazol-1-yl]butane (L⁴) and 1,8-bis[4-(4,4,5,5-tetramethyl-3-oxide-1-oxyl-4,5-dihydro-1H-imidazol-2-yl)pyrazol-1-yl]octane (L⁸) gave respectively a framework compound [Cu(hfac)₂]₂L⁴ and a layered polymer compound[Cu(hfac)₂]₂L⁸. The framework of [Cu(hfac)₂]₂L⁴ consists of 66-membered condensed metallocycles. Inside theframework, the structure has macrohelixes (pitch ~25 Å) extending along the [001] crystallographic direction. Allthe helixes have the same direction of winding; the crystals, therefore, are optically active, the structure correspondingeither to P-isomer (P4₁2₁2) or to M-isomer (P4₃2₁2). The long distances between the Cu atoms and the O atomsof the coordinated >N-O groups (Cu-O 2.351-2.467 Å) are responsible for ferromagnetic exchange interactionsin Cu²⁺-O-N< and >N-O-Cu²⁺-O-N< exchange clusters.