Magnetism of Self assemblies Consisting of Single-molecule Magnets

针对基于异位旋体系策略的单分子磁体的组装进行了研究。用2-和6-位含二甲氨基的三齿吡啶配体与二吡啶重氮甲烷(D1py_2)形成的钴配合物，制备了哑铃型双核单分子磁体。在交流磁化率测量中，辐照后的络合物对SMM表现出缓慢的磁弛豫特性。然而，不能得到能够进行X射线晶体结构分析的晶体。Co(p-Tolsal)_2和D_1py_2以1：1的比例混合得到的钴络合物提供了表明ID链形成的扫描电子显微镜照片。在辐照后的晶体样品的直流磁化率测量中，得到了钴离子和卡宾的8个单元以铁磁性相互作用的结果。此外，该钴配合物在交流磁化率测量中表现出缓慢的磁弛豫，在交流磁化率测量中表现出U&lt；Jeff&gt；=87K的磁驰豫，在直流磁化率测量中表现出磁滞回线，其磁滞回线的Hc=900Oe。这些结果表明形成了一条ID链。X-射线结构分析表明，类似于Co(HFAc)_2的Co(Hfaci)_2与D1py_2和D2py_2形成的配合物分别具有ID链和2：2的环状结构。它们表现出独特的磁性行为，分别受到链间和分子间反铁磁相互作用的强烈影响。

The studies aiming at the assemblization of single-molecule magnets (SMMs) based on the strategy of heterospin system have been proceeded. Dumbbell-type dinuclear single-molecular magnet was prepared by using the cobalt complex with tridentate pyridine ligand having dimethylamino groups at 2-and 6-position and dipyridildiazomethane (D1py_2). After irradiation, the complex showed slow magnetic relaxation characteristic to SMM in ac magnetic susceptibility measurements. However, the crystal amenable to X-ray crystal structure analysis could not be obtained. The cobalt complex obtained by mixing Co(p-tolsal)_2 and D1py_2 in 1:1 ratio, provide the SEM picture suggesting the formation of ID chains. In the dc magnetic susceptibilities measurement of the crystal sample after irradiation, the result indicating that the eight units of the cobalt ion and carbene interact ferromagnetically, was obtained. Furthermore, this cobalt complex showed a slow magnetic relaxation with U_<eff> = 87 K in ac magnetic susceptibility measurement and a hysteresis loop with H_c = 900 Oe in dc magnetic susceptibility measurement. These results indicate the formation of a ID chain. The complexes of Co(hfaci)_2, which is analogous to Co(hfac)_2, with D1py_2 and D2py_2 have a ID chain and a 2:2 cyclic structure, respectively, which were determined by X-ray structure analysis. They showed unique magnetic behaviors strongly affected by the interchain and intermolecular antiferromagntic interactions, respectively.