基于5-羟甲基间苯二甲酸和咪唑衍生物的半导体型Ni-MOFs的合成、晶体结构和光催化性质

Semiconductive Ni-MOFs Based on 5-(Hydroxymethyl) Isophthalic Acid and Imidazole Derivatives: Synthesis, Crystal Structures, and Photocatalytic Properties

利用水热反应制备了2个配合物{[Ni(HIPA)(2,5-DPBI)_(1.5)(H_(2)O)]·2.25H_(2)O}_(n)(1)和[Ni(HIPA)(2,5-DPBMI)(H_(2)O)]_(n)(2)(H_(2)HIPA=5-(羟甲基)间苯二甲酸,2,5-DPBI=1,1’-(2,5-二甲基-1,4-亚苯基)双(1H-咪唑),2,5-DPBMI=1,1’-(2,5-二甲基-1,4-亚苯基)双(4-甲基-1H-咪唑))。结构分析揭示在不同咪唑配体存在下,配合物的Ni中心具有不同的配位环境。配合物1具有拓扑符号为(4~2.6~6.8~2)的五连接三维框架,而配合物2则是dia型的四连接网络。粉末X射线衍射证实配合物1和2在有机溶剂和紫外可见光照射的水中均非常稳定。此外,紫外可见吸收谱、Mott-Schottky和电化学阻抗谱(EIS)测试显示配合物1和2都是典型的n型半导体材料,具有较低的电荷传输阻抗。在光催化实验中,配合物1和2对染料亚甲基蓝的降解有催化活性。

Two complexes{[Ni(HIPA)(2,5-DPBI)_(1.5)(H_(2) O)]·2.25 H_(2) O}_(n)}(1)and[Ni(HIPA)(2,5-DPBMI)(H_(2) O)]_(n)(2)(H_(2) HIPA=5-(hydroxymethyl)isophthalic acid,2,5-DPBI=1,1’-(2,5-dimethyl^(-1),4-phenylene)bis(1 H-imidazole),2,5-DPBMI=1,1’-(2,5-dimethyl^(-1),4-phenylene)bis(4-methyl^(-1) H-imidazole))were synthesized via hydrothermal method.Structural analysis reveals that Ni(Ⅱ)centers have different coordination environments in the existence of different imidazole ligands.As a result,complex 1 possesses a 5-connected framework with the topological symbol of(4~2.6~6.8~2),while complex 2 shows a 4-connected framework with dia net.The powder X-ray diffraction further firms that complexes 1 and 2 are very stable not only in a normal organic solvent but also in water under UV light.Moreover,the UV-Vis spectra,Mott-Schottky measurements,and electrochemical impedance spectroscopy(EIS)demonstrate that complex 1 and 2 are typical n-type semiconductors with low resistance in charge transportation.Finally,photocatalytic tests confirm that complexes 1 and 2 have catalytic activity for the degradation of methylene blue.CCDC:2114481,1;2114482,2.