基于线性叠氮四核单元的系列二维化合物：合成,晶体结构及磁性(英文)

A Series of 2D Coordination Polymers Based on Unprecedented Linear Tetranuclear Units Bridged by the Azido Anion:Syntheses,Crystal Structures and Magnetic Properties

分子磁体的设计与合成一直是当今物理和化学的热门研究课题.受分子磁体启发,通过引入叠氮磁耦合基团以及长链棒状配体4,4'-二咪唑联苯(L),我们构筑了三个磁性化合物[Co2(N3)4(L)2.5]∞(1),[Ni2(N3)3(NO3)(L)2.5]∞(2)和[Mn2(N3)4(L)2.5]∞(3).结构分析显示,这是三个同构化合物,展现了一种基于线性叠氮四核单元的二维层网络.有意义的是,这种线性叠氮四核单元还未曾被人报道.磁性研究表明,三个化合物都是铁磁耦合,这是由于EO-叠氮所导致的.通过拟合实验数据,我们得到了三个化合物的磁耦合常数,进一步验证了上面磁构相关性的讨论.

Sparked by the strategy of molecular magnets, three magnetic coordination polymers, [C02（N3）4（L）2.5]∞ （1）, [Ni2（N3）3（NOa）（L）2.5]∞（2） and [MnE（N3）4（L）2.5]∞（3） （L=4,4＇-bis（imidazol-l-yl）biphenyl）, have been synthesized by employing azide as the coupling carrier and a rod-like ligand L as the magnetic insulator. Structural analysis indicates that complexes 1-3 are iso-structural, and illustrate a 2D （4,4） layer based on unprecedented linear tetranuclear units bridged by the EO-azido ions. Their magnetic measurements revealed that complexes 1-3 all present the ferromagnetic （FM） coupling, which was due to the EO-azido linker. The corresponding exchange coupling constants have been estimated by fitting the experimental data, which confirmed the above magneto-structural correlations.