基于1,3-二(2-苯并咪唑基)苯的双核钴及钴配位聚合物的晶体结构及磁性 |
Binuclear Cobalt(Ⅱ) Complex and Cobalt(Ⅱ) Coordination Polymer of Bidentate Ligand 1,3-Bis(2-benzimidazolyl)benzene: Crystal Structures and Magnetic Properties |
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摘要: 在不同的条件下, 合成了2个基于刚性配体MBimB的钴配合物, 即Co2(MBimB)2Cl4·2H2O·EDA (1)和[Co(MBimB)Cl2]n (2)(MBimb=1, 3-二(2-苯并咪唑基)苯, EDa=乙二胺), 并解析了其单晶结构。在配合物1中, 2个MBimB配体采用顺式构象桥接2个钴原子, 形成双核金属杂环结构。在配合物2中, MBimB配体采用反式配位方式, 桥接2个邻近的钴原子, 形成一维链状结构。磁性研究表明:随温度降低, 配合物1和2均先表现为铁磁耦合, 继而表现为反铁磁耦合。同配合物2相比, 配合物1中Co…Co原子距离更短, 且存在更强的π共轭效应, 因此, 配合物1中存在更为强烈的铁磁耦合及旋轨耦合作用。 |
关键词: 1, 3-二(2-苯并咪唑基)苯 配位聚合物 双核钴配合物 磁性 |
基金项目: 国家自然科学基金(No.21371105, 51372125, 51179182), 青岛市科技发展计划(No.14-2-4-41-jch, 13-1-4-209-jch)资助项目。 |
Abstract: Two cobalt(Ⅱ) complexes, Co2(MBimB)2Cl4·2H2O·EDA (1) (MBimb=1,3-bis(2-benzimidazolyl)benzene, EDa=ethylenediamine) and [Co(MBimB)Cl2]n (2), have been synthesized based on the rigid ligand MBimB and characterized by single crystal X-ray diffraction. In complex 1, two MBimB molecules adopt "cis" conformation and bridge two cobalt(Ⅱ) ions to form a binuclear metallaycyclic framework. In complex 2, MBimB ligand adopts "trans" conformation and bridges two adjacent cobalt(Ⅱ) ions into 1D zigzag chain. Magnetic susceptibility of 1 and 2 showed ferromagnetic coupling firstly and then antiferromagnetic coupling as the temperature decreases. Compared to complex 2, stronger ferromagnetic interaction and/or spin-orbital coupling between the cobalt(Ⅱ) ions in 1 can be ascribed to the shorter distance of Co…Co and enhanced intervening aromatic π-system between the metal centers. |
Keywords: 1, 3-bis(2-benzimidazolyl)benzene coordination polymer binuclear cobalt(Ⅱ) complex magnetic properties |
投稿时间:2015-02-28 修订日期:2015-04-02 |
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刘法谦,赵杰,张东,段小群,王磊,邓月义,李伟华.基于1,3-二(2-苯并咪唑基)苯的双核钴及钴配位聚合物的晶体结构及磁性[J].无机化学学报,2015,31(7):1402-1408. |
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