化学学报 ›› 2014, Vol. 72 ›› Issue (4): 447-455.DOI: 10.6023/A14010029 上一篇    下一篇

研究论文

自组装中的苯二甲酸阴离子形貌及质子化效应

周丽a, 徐立进a, 龚汉元b   

  1. a 中国人民大学化学系 北京 100872;
    b 北京师范大学化学学院 北京 100875
  • 收稿日期:2014-01-10 出版日期:2014-04-14 发布日期:2014-02-06
  • 通讯作者: 徐立进 E-mail:xulj@chem.ruc.edu.cn;龚汉元 E-mail:hanyuangong@bnu.edu.cn E-mail:xulj@chem.ruc.edu.cn;hanyuangong@bnu.edu.cn
  • 基金资助:

    项目受国家自然科学基金(Nos.21202199,21372258)资助.

Pattern and Protonation Effect of Benzene Dicarboxylate Anion Species in Self-assembly System

Zhou Lia, Xu Lijina, Gong Hanyuanb   

  1. a Department of Chemistry, Renmin University of China, Beijing 100872;
    b College of Chemistry, Beijing Normal University, Beijing 100875
  • Received:2014-01-10 Online:2014-04-14 Published:2014-02-06
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Nos. 21202199, 21372258).

在高效合成大环主体化合物环[2][2,6-二(1H-咪唑基)]吡啶[2](1,4-二亚甲基苯)[cyclo[2](2,6-bis(1H-imidazol-1-yl)pyridine)[2](1,4-dimethylenebenzene);14+]的基础上,通过溶液中核磁1H谱、扩散排序核磁共振谱(Diffusion Ordered NMR Spectroscopy;DOSY)、二维核磁欧沃豪斯效应增强谱(Nuclear Overhauser Effect Spectroscopy;NOESY)波谱方法,气相中质谱(ESI-MS)及固相中X射线单晶衍射方法,详细考察14+与一系列苯二甲酸阴离子客体的相互作用. 发现苯二甲酸阴离子客体的形貌与质子化因素对主客体的作用模式、相互作用的化学计量比以及形成超分子自组装复合物的结合常数均起着决定性的作用. 本文结果将有助于指导后继新型大环主体化合物与多羧酸阴离子构筑的自组装体系的设计和研究.

关键词: 大环主体化合物, 苯二甲酸阴离子, 主客体化学, 非键弱相互作用, 作用模式

A novel macrocycle host with flexible structure and big cavity, cyclo[2](2,6-bis(1H-imidazol-1-yl)- pyridine)[2](1,4-dimethylenebenzene) (i.e. 14+), was effectively synthesized through cyclization reaction between 1,4-bisbromo-methylbenzene and 2,6-di(1H-imidazol-1-yl)pyridine. The binding and self-assembly properties of macrocycle host 14+ with a series of benzene dicarboxylate anion guests (i.e. mono-terephthalate anion 2, di-terephthalate anion 3, mono-isophthalate anion 4, di-isophthalate anion 5, mono-phthalate anion 6 or di-phthalate anion 7) were studied in detail via 1H NMR spectroscopy, diffusion ordered NMR spectroscopy (DOSY), nuclear Overhauser effect spectroscopy (NOESY) in solution, electrospray ionization mass spectrometry (ESI-MS) in gas phase, and X-ray single crystallography in solid state. The result implied that macrocycle host 14+ and mono-terephthalate anion (2) or di-isophthalate anion (5) form pseudorotaxane structure, even more complex supramolecular self-assembly structure (e.g. pseudo-oligarotaxne ). Meanwhile the other guest anions adopt the "outside" binding modes in the complexation with 14+. It is also found that the thermodynamic equilibrium(s) and association constants of the complexes between macrocycle host 14+ and a series of benzene dicarboxylate anion guest species are different via 1H NMR Job-plots and 1H NMR spectroscopic titrations in solution: (1) the stoichiometry values suggested that host 14+ can bind equivalent or more mono-anion guests than di-anion species from the same benzene dicarboxylic acid; (2) comparing the association constants of 1:1 (host:guest) complex between 14+ and mono-anion species resulted in Ka[14+·2]>Ka[14+·4]>Ka[14+·6]; the similar comparison was carried out for di-anion species interactions and obtained Ka[14+·3]>Ka[14+·5]>Ka[14+·7]; the result suggest that the pattern of the anion highly influences the thermostability of the 1:1 complex. It is speculated that the pattern and protonation factors of the benzene dicarboxylate anion guests determine their interactions with macrocycle 14+, including binding modes, stoichiometries, association constants, and so on. The finding will help to direct the following novel supramolecular self-assembly construction involving macrocycle host and multi-carboxylate anion species.

Key words: macrocylic host compound, benzene dicarboxylate anions, host-guest chemistry, non-covalent weak interactions, complexation mode