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.