高等学校化学学报 ›› 2004, Vol. 25 ›› Issue (11): 2038-2041.

• 研究论文 • 上一篇    下一篇

葫[n]环联脲(n=5,6,7,8)与两种重氮氟硼酸盐的包合作用研究

刘思敏1, 吴晓军1, 梁峰1, 姚骏骅2, 吴成泰1   

  1. 1. 武汉大学化学与分子科学学院, 武汉430072;
    2. 中山大学测试中心, 广州510275
  • 收稿日期:2003-08-11 出版日期:2004-11-24 发布日期:2004-11-24
  • 基金资助:

    国家自然科学基金(批准号:20172040)资助

Inclusion Complexation Between Cucurbit[n]uril(n=5,6,7,8) and Two Diazonium Tetrafluoroborates

LIU Si-Min1, WU Xiao-Jun1, LIANG Feng1, YAO Jun-Hua2, WU Cheng-Tai1   

  1. 1. Department of Chemistry, Wuhan University, Wuhan 430072, China;
    2. Instrumentation Analysis and Research Center, Sun Yat-Sen University, Guangzhou 510275, China
  • Received:2003-08-11 Online:2004-11-24 Published:2004-11-24

摘要: 用核磁共振氢谱和紫外-可见光谱滴定法考察了葫[n]环联脲(Cucurbit[n]uril,n=5,6,7,8)与对甲苯重氮氟硼酸盐和4,4′-联苯二重氮氟硼酸盐的配位情况,并用曲线拟合求得形成的包结配合物的稳定常数.结果表明,不同空腔的葫[n]环联脲对不同尺寸的重氮氟硼酸盐具有很显著的选择性包结作用.在相同条件下,与葫[6]环联脲相比,葫[7]环联脲更易于容纳苯环.同时,随着酸性的增强,葫[n]环联脲上的脲羰基质子化程度加大,使得其配位能力有所减弱.

关键词: 葫[n]环联脲, 包结配位, 重氮盐, 分子识别

Abstract: Inclusion complexation between cucurbit[n]uril(CB[n], n=5,6,7,8) and two diazonuim salts in various acid solutions was investigated by 1H NMR spectroscopy and UV-Vis spectrophotometric titration. The binding constants were obtained by using a non-linear least squares curve fitting. The inclusion of diazonuim ions in the cavity of CB[n] made 1H NMR spectra of diazonuim ions moving towards a higher magnetic field. The results indicated that CB[5] and CB[8] couldn′t include the two kinds of diazonium ions efficiently. The cavity of CB[6] was too small to accommodate 4,4′-biphenylene-bis-diazonium ions. CB[7] could contain both p-methylbenzene diazonium and 4,4′-biphenylene-bis-diazonium ions. In contrast to CB[6], CB[7] was more suitable for holding p-methylbenzenediazonium ion, showing that the complex stability is dominated by the size/shape-matching between the host and guest. With increasing the concentration of the acid, the measured binding constants decreased notablely, due to the competitive complex of protons with carbonyls of CB[n].

Key words: Cucurbit[n]uril, Inclusion complexation, Diazonium salts, Molecular recognition

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