基于构象灵活的N-杂环配体构筑的3D拟卤化亚铜配合物的合成、结构和性质研究

溶剂热条件下,通过无机阶梯状链[Cu(SCN)]_n与柔性有机配体1,3-二(4-吡啶基)丙烷(bpp)自组装,得到了一例新型的3D有机-无机杂化配合物[Cu₄(SCN)₄(bpp)₂]_n (1)。值得关注的是,不对称单元中的bpp配体显示两种不同的构象(trans-gauche或trans-trans),并连接梯形的[Cu(SCN)]_n链形成结晶学独立的[Cu₂(SCN)₂(bpp)]_n (A和B)层。紧接着, 两个不同的层通过ABB′A′的顺序排列形成独特的三维褶皱结构。进一步对配合物1进行了红外光谱(FT-IR)、粉末衍射(PXRD)、热分析、固体紫外-可见漫反射光谱(UV-Vis)和光致发光性质研究。固体紫外-可见光谱表明配合物在紫外区有强的吸收并且具有半导体性质,带隙能E_g为3.20 eV。光催化性能测试结果表明,配合物1在紫外光照射下对中性红(NR)、甲基橙(MO)、天青I(AI)、亚甲基蓝(MB)和亮蓝(ED)这五种染料表现出不同的光催化活性,这可能与有机染料的尺寸和电荷差异有关。此外,荧光测试表明配合物在室温下表现出较强的绿色发光性质,在525 nm附近有强的荧光发射峰。这种发射可能与配体中心激发态有关,可能涉及金属到配体或配体到配体的电荷转移。

Synthesis,Structure and Properties of 3D Copper(I) Pseudohalide Compound Constructed by Conformationally Flexible N-Heterocylic Ligand

A new 3D organic-inorganic hybrid solid [Cu₄(SCN)₄(bpp)₂]_n (1) was obtained via the self-assembly of inorganic ladder-like chains [Cu(SCN)]_n with the flexible organic ligands 1,3-di(4-pyridyl)propane (bpp) under solvothermal conditions. It is noted that the bpp ligands show two kinds of conformations (trans-gauche or trans-trans) in the asymmetric unit, which linked by similar staircase-like [Cu(SCN)]_n chains to form crystallographically distinct [Cu₂(SCN)₂(bpp)]_n layers A and B. Furthermore, two different layers are packed in an offset ABB′A′ pattern to generate unique 3D structure. Compound 1 was further characterized by infrared spectroscopy (FT-IR), powder diffraction (PXRD), thermal analysis, solid state diffuse reflectance spectroscopy (UV-Vis) and photoluminescent studies. The solid UV-Vis diffuse-reflectance spectroscopy shows strong absorption spectra in ultraviolet region, and a wide-gap semiconductor with band gap of 3.20 eV. Compound 1 shows different photocatalytic activities for neutral red (NR), methyl orange (MO), azure I (AI), methylene blue (MB) and brilliant blue (ED) degradation under UV-light irradiation, which could be related to the slight charge and size difference of organic dyes. Compound 1 shows strong green photoluminescence at room temperatures with emission peaks at about 525 nm, which may be associated with a ligand-centered excited state with a possible involvement of metal-to-ligand or ligand-to-ligand charge transfer.