Furui Takanori, Suzuki Shuichi, Kozaki Masatoshi, Shiomi Daisuke, Sato Kazunobu, Takui Takeji, Okada Keiji, Tretyakov Evgeny V, Tolstikov Svyatoslav E, Romanenko Galina V, Ovcharenko Victor I
Department of Chemistry, Graduate School of Science, Osaka City University , Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan.
Inorg Chem. 2014 Jan 21;53(2):802-9. doi: 10.1021/ic4020898. Epub 2013 Dec 23.
Metal complexation reactions of N-t-butyl-N-oxidanyl-2-amino(nitronyl nitroxide) diradical (1) with M(hfac)2 (M: Mn or Cu) were investigated. These reactions were found to be very sensitive to the type of metal ion employed. Complex [Mn(hfac)2·1], consisting of Mn(hfac)2 and diradical 1, was readily prepared by mixing the components. However, the reaction of Cu(hfac)2 with 1 or N-t-butyl-N-oxidanyl-2-amino(iminonitroxide) diradical (2) involved the reduction of the diradical to the N-t-butyl-N-oxidanide-2-amino(iminonitroxide) radical anion (3) and finally produced the polymer-chain complex [Cu2(hfac)2·32·Cu(hfac)2]n. The structures of these complexes were elucidated by X-ray analysis, and their magnetic properties were investigated in detail. The temperature dependence of χpT (χp: magnetic susceptibility) for [Mn(hfac)2·1] exhibited a strong antiferromagnetic interaction (H = -2JS1·S2, J/kB = -217 K) between the Mn(II) spin (S = 5/2) and the diradical 1 spin (S = 1). However, the χpT-T plots for [Cu2(hfac)2·32·Cu(hfac)2]n indicated the presence of several magnetic interactions: a large ferromagnetic interaction (J/kB = 510 K) between iminonitroxide 3 and the imino-coordinating Cu(II) atom, a moderately large ferromagnetic interaction (J/kB = 58 K) between the iminonitroxide and (iminonitroxide oxygen)-coordinating Cu(hfac)2, and a weak antiferromagnetic interaction (J/kB = -1.4 K) between the two Cu(hfac)-3 moieties within a Cu2O2 square.
研究了N-叔丁基-N-氧化-2-氨基（硝酮硝酰基）双自由基（1）与M（hfac）2（M：Mn或Cu）的金属络合反应。发现这些反应对所使用的金属离子类型非常敏感。由Mn（hfac）2和双自由基1组成的配合物[Mn（hfac）2·1]，通过混合各组分很容易制备。然而，Cu（hfac）2与1或N-叔丁基-N-氧化-2-氨基（亚氨基硝酰基）双自由基（2）的反应涉及双自由基还原为N-叔丁基-N-氧化-2-氨基（亚氨基硝酰基）自由基阴离子（3），最终生成聚合物链配合物[Cu2（hfac）2·32·Cu（hfac）2]n。通过X射线分析阐明了这些配合物的结构，并详细研究了它们的磁性。[Mn（hfac）2·1]的χpT（χp：磁化率）对温度的依赖性在Mn（II）自旋（S = 5/2）和双自由基1自旋（S = 1）之间表现出强烈的反铁磁相互作用（H = -2JS1·S2，J/kB = -217 K）。然而，[Cu2（hfac）2·32·Cu（hfac）2]n的χpT-T图表明存在几种磁相互作用：亚氨基硝酰基3与亚氨基配位的Cu（II）原子之间存在大的铁磁相互作用（J/kB = 510 K），亚氨基硝酰基与（亚氨基硝酰基氧）配位的Cu（hfac）2之间存在中等大小的铁磁相互作用（J/kB = 58 K），以及在Cu2O2正方形内两个Cu（hfac）-3部分之间存在弱的反铁磁相互作用（J/kB = -1.4 K）。
