2-(4-吡啶基)咪唑二羧酸锌配位聚合物的自发拆分

Spontaneous Resolution of Zinc Coordination Polymers with 2-(4-Pyridyl)imidazole-4,5-dicarboxylic Acid

  • 摘要: 非手性配体2-(4-吡啶基)-4,5-咪唑二羧酸(H2L)与硝酸锌进行水热反应得到组成为ZnLn?2nH2O的自发拆分的2种三维金属-有机框架手性晶体,空间群分别为P41212和P43212,其中配位多面体分别为和型Zn(NO)2N三角双锥结构. 两种晶体分别存在着约0. 2 nm宽的不同手性的超微四方孔道,容纳的结晶水分子通过氢键分别形成右手和左手螺旋. 320 ℃以下主体框架保持稳定. 晶体在440 nm左右的荧光发射相比配体增强2倍以上. 该研究对于由非手性原料合成手性多空材料的进一步研究具有积极意义.

     

    Abstract: Solvothermal reaction between achiral 2-(4-pyridyl)imidazole-4,5-dicarboxylic acid (H2L) and zinc nitrate afforded two spontaneously resolved three-dimensional metal-organic frameworks formulated as ZnLn?2nH2O, with the space group being P41212 and P43212 respectively. The coordination polyhedral are - and -Zn(NO)2N trigonal bipyramidal geometries, respectively. There are about 0.2 nm wide ultramicroporous channels with different chiralities, among which are the right- and left-handed helix of water chains formed by hydrogen bonds. The main frameworks keep stable under 320 ℃. The fluorescence of the crystals is enhanced over two times than that of the free ligand. The present work is helpful for further studies on constructing chiral porous materials with achiral starting substances.

     

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