化学学报 ›› 2012, Vol. 70 ›› Issue (17): 1775-1778.DOI: 10.6023/A12060296 上一篇    下一篇

研究论文

1,4-双正丙氧基柱[7]芳烃的合成及主客体化学

韩成友, 张子彬, 池小东, 张明明, 喻国灿, 黄飞鹤   

  1. 浙江大学化学系 杭州 310027
  • 收稿日期:2012-06-11 出版日期:2012-09-14 发布日期:2012-07-17
  • 通讯作者: 黄飞鹤
  • 基金资助:
    项目受国家自然科学基金(Nos. 20834004和91027006)资助.

Synthesis of 1,4-Bis(n-propoxy)pillar[7]arene and Its Host-guest Chemistry

Han Chengyou, Zhang Zibin, Chi Xiaodong, Zhang Mingming, Yu Guocan, Huang Feihe   

  1. Department of Chemistry, Zhejiang University, Hangzhou 310027, China
  • Received:2012-06-11 Online:2012-09-14 Published:2012-07-17
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Nos. 20834004 and 91027006).

我们以1,4-二正丙氧基-2,5-双甲氧甲基苯为原料用对甲苯磺酸为催化剂在二氯甲烷中制备了1,4-双正丙氧基柱[5]芳烃, 1,4-双正丙氧基柱[6]芳烃和1,4-双正丙氧基柱[7]芳烃. 我们用氢谱, 碳谱和质谱对它们进行了表征. 它们有不同的氢谱却有相似的碳谱. 对比它们的空腔尺寸, 柱[5]的内径大约是4.6 Å, 与葫芦脲[6]及α-环糊精类似. 柱[6]的内径大约是6.7 Å, 与葫芦脲[7]及β-环糊精类似. 柱[7]的内径大约是8.7 Å, 与葫芦脲[8]及γ-环糊精类似. 我们用正辛基三乙基六氟磷酸铵盐作为模型客体研究了它们之间的主客体络合. 柱[5]与之有微弱的络合, 柱[6]显示了良好的络合, 而柱[7]与之没有络合.

关键词: 大环, 主客体化学, 超分子化学, 柱芳烃, 自组装

Pillar[n]arenes, as a new type of macrocyclic hosts, have attracted more and more attention in recent years. Their repeating units are connected by methylene bridges at the para-positions so they have a pillar architecture, which is different from the basket-shaped structure of meta-bridged calixarenes. Herein, 1,4-Bis(n-propoxy)pillar[5]arene (P5), 1,4-bis(n-propoxy)pillar[6]arene (P6) and 1,4-bis(n-propoxy)pillar[7]arene (P7) were synthesized from the condensation of 1,4-di(n-propoxy)-2,5-bis(methoxymethyl)benzene using p-toluenesulfonic acid as the catalyst in dichloromethane. They were characterized by 1H NMR, 13C NMR and mass spectrometry. They had different 1H NMR spectra but similar 13C NMR spectra. The diameter of the internal cavity of P5 is ca. 4.6 Å, similar to those of cucurbit[6]uril (ca. 5.8 Å) and α-cyclodextrin (ca. 4.7 Å). The diameter of the internal cavity of P6 is ca. 6.7 Å, similar to those of cucurbit[7]uril (ca. 7.3 Å) and β-cyclodextrin (ca. 6.0 Å). The diameter of the internal cavity of P7 is ca. 8.7 Å, similar to those of cucurbit[8]uril (ca. 8.8 Å) and γ-cyclodextrin (ca. 7.5 Å). The host-guest binding properties of them were investigated with n-octyltriethyl ammonium hexafluorophosphate G as a model guest. P6 showed complexation with G while weak complexation was observed between G and P5, but no complexation occurred between P7 and G. The 1H NMR spectrum of an equimolar solution of P6 and G in chloroform-d showed only one set of peaks, indicating fast-exchange complexation between P6 and G on the 1H NMR time scale at 22 °C. A mole ratio plot indicated that the complexation stoichiometry was 1:1 between P6 and G. This was further confirmed by a low resolution electrospray ionization mass spectroscopy peak at m/z 1451.7 corresponding to [P6G - PF6]+. The association constant of the 1∶1 complex P6G in chloroform-d was determined to be (740±86) L·mol-1 by a proton NMR titration. These experiments demonstrate that G fits the cavity of P6 while it is too big for the cavity of P5 and too small for the cavity of P7.

Key words: macrocycles, host-guest chemistry, supramolecular chemistry, pillararenes, self-assembly