Abstract

Two novel porous zinc metal-organic frameworks (MOFs) 1 and 2 based on 1,1′-bis-((3,5-dicarboxybenzyl)-4,4′-bipyridinium) dichloride (H₄bdcbpy·2Cl) ligand have been successfully synthesized by solvothermal reactions at different temperatures. Compounds 1 and 2 have the same composition but crystallize in different crystal systems. Compound 1 synthesized at low temperature crystallizes in the monoclinic system, and compound 2 prepared at high temperature crystallizes in the rhombohedral system. The structural differences of two compounds indicate that temperature plays an important role in the formation of the Zn-based MOFs. The Zn²⁺ ions are bridged by deprotonated formic acid moieties to form a 3D network in both compounds. H₄bdcbpy·2Cl provided an acidic environment, which led to the decomposition of DMF into a rare C₃H₂N₂²⁺ cation. Nitrogen adsorption measurement displays that the adsorption capacity of 1 is 711 m² g^–1. The fluorescence spectra of compound 1 shows that there is a strong emission peak at 527 nm.

中文翻译：

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温度调节的两种具有发光特性的新型 3D Zn(II) 金属有机骨架

摘要

两种基于 1,1'-双-((3,5-二羧基苄基)-4,4'-联吡啶鎓) 二氯化物 (H ₄ bdcbpy·2Cl) 配体的新型多孔锌金属有机骨架 (MOF) 1和2在不同温度下通过溶剂热反应成功合成。化合物1和2具有相同的组成但在不同的晶系中结晶。低温合成的化合物1在单斜晶系中结晶，高温合成的化合物2在菱面体晶系中结晶。两种化合物的结构差异表明温度在锌基 MOF 的形成中起着重要作用。锌²⁺离子通过去质子化的甲酸部分桥接，在两种化合物中形成 3D 网络。H ₄ bdcbpy·2Cl 提供了酸性环境，导致DMF 分解成稀有的C ₃ H ₂ N ₂ ²⁺阳离子。氮吸附测量显示1的吸附容量为711 m ² g ^–1。化合物1的荧光光谱表明在527 nm处有一个强发射峰。