Five new coordination polymers, [Cd₂(Hmidc)₂(bpp)]·2H₂O (1), [Zn₃(midc)₂(bpp)(H₂O)₂]·2H₂O (2), [Me₂NH₂]₂[Zn₃(midc)₂(HCOO)₂] (3), [Mg(Hmidc)(H₂O)₂]·H₂O (4), and [Co(Hmidc)(bpp)] (5) (bpp = 1,3-bis(4-pyridyl) propane, H₃midc = 2-methyl-1H-imidazole-4,5-dicarboxylic acid), were synthesized. Compounds 1–3 feature 3D pillar-layered networks with different topologies, in which the H₃midc ligand coordinantes with Zn²⁺/Cd²⁺ to form a layer and bpp or HCOO^– bridges the adjacent layers as a pillar. In compound 4, however, unanticipated 1D chains connect with each other through hydrogen bonds, resulting in a 3D supramolecular framework. Compound 5 displays a wavelike chain form. The UV–vis absorption spectra and the calculations of density of states demonstrate that the emission spectra of compounds 1–4 result from ligand-centered charge transition. The solid-state luminescence quantum yield of compound 3 reaches up to 20.69%. In addition, compound 1 has a preferable gas adsorption selectivity of CO₂ over CH₄ and N₂ in natural gas at low pressure.

中文翻译：

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精确调节2-甲基-1 H-咪唑-4,5-二羧酸配体的配位模式，以适应一系列具有不同结构和性质的金属有机化合物

五个新的配位聚合物，[Cd ₂（Hmidc）₂（bpp）]·2H ₂ O（1），[Zn ₃（midc）₂（bpp）（H ₂ O）₂ ]·2H ₂ O（2），[ Me ₂ NH ₂ ] ₂ [Zn ₃（midc）₂（HCOO）₂ ]（3），[Mg（Hmidc）（H ₂ O）₂ ]·H ₂ O（4）和[Co（Hmidc）（bpp） ）]（5）（bpp = 1,3-双（4-吡啶基）丙烷，H ₃ midc = 2-甲基-1 H-咪唑（4，5-二羧酸）被合成。化合物1 - 3具有不同的拓扑结构，在将H特征3D柱状分层网络₃ MIDC配体用Zn coordinantes ²⁺ / CD ²⁺以形成层和BPP或HCOO ^-桥接相邻层作为支柱。但是，在化合物4中，未预料到的1D链通过氢键相互连接，从而形成3D超分子框架。化合物5显示出波状链形式。紫外-可见吸收光谱和态密度的计算结果表明，化合物的发射光谱1 - 4由以配体为中心的电荷跃迁产生。化合物3的固态发光量子产率高达20.69％。另外，化合物1在低压下对天然气具有比CH ₄和N ₂更好的CO ₂气体吸附选择性。