一例铽簇合物的合成、晶体结构与磁性

Synthesis,Crystal Structure and Magnetic Property of a Terbium Cluster

本文以2, 6-二甲氧基苯酚和硝酸铽为原料,成功合成了一例新型九核铽簇合物{Tb_(9)(L)_(4)(μ_(4)-OH)2(μ_(3)-OH)_(8)(μ_(2)-OCH_(3))_(4)(NO_(3O))_(8)(H_(2)O)_(8)}(OH)·2H_(2)O(1),其中HL为2, 6-二甲氧基苯酚。通过X射线衍射、元素分析、红外光谱、热重和磁性测试对该簇合物进行表征。X射线单晶衍射分析结果表明,簇合物属于正交晶系,空间群为I222,晶胞参数为a=1.532 8(3) nm,b=1.796 9(4) nm,c=1.863 5(4) nm,α=β=γ=90°,V=5.132 6(19) nm^(3)。簇合物中九个金属中心由μ_(4)-OH和μ_(3)-OH相互连接,形成的骨架呈现出有趣的沙漏状拓扑结构,其中,中心Tb离子呈现出稍微扭曲的四方棱锥几何构型,其他Tb离子均为稍变形的十二面体构型。磁性测试结果表明,簇合物1中的金属离子之间存在弱的反铁磁相互作用,由于快速的磁量子隧穿效应,其未表现出慢磁弛豫行为。

In this paper,a new nonanuclear terbium cluster{Tb_(9)(L)_(4)(μ_(4)-OH)2(μ_(3)-OH)_(8)(μ_(2)-OCH_(3))_(4)(NO_(3O))_(8)(H_(2) O)_(8)}(OH)·2H_(2) O(1)was synthesized by 2,6-dimethoxyphenol(HL)and Tb(NO_(3O))2·6H_(2) O.The cluster was characterized via XRD,elemental analysis,infrared spectrum and thermogravimetric analysis.The magnetic property were also studied.X-ray single-crystal diffraction analysis indicates that the cluster is orthorhombic,the space group is I222,the crystal cell parameters are a=1.5328(3)nm,b=1.7969(4)nm,c=1.8635(4)nm,α=β=γ=90°,V=5.1326(19)nm^(3).The nonanuclear skeleton formed by metal centers in the cluster that connected byμ_(4)-OH andμ_(3)-OH presents an interesting hourglass like topology.The central Tb ion has a slightly twisted tetragonal pyramid geometry,while the other Tb ions have a slightly deformed dodecahedral configuration.Magnetic investigations reveal that the weak antiferromagnetic interactions between adjacent metal ions exist in cluster 1,but no obvious slow magnetic relaxation behavior is shown due to the rapid magnetic quantum tunneling effect.