Inclusion Complex Formation of Ionic Liquids and Other Cationic Organic Compounds with Cucurbit[7]uril Studied by 4242;,6-Diamidino-2-phenylindole Fluorescent Probe
详细信息 查看全文
- 作者：Zsombor Miskolczy ; Lszl Biczk ; Mnika Megyesi ; Istvn Jablonkai
- 刊名：Journal of Physical Chemistry B
- 出版年：2009
- 出版时间：February 12, 2009
- 年：2009
- 卷：113
- 期：6
- 页码：1645-1651
- 全文大小：198K
- 年卷期：v.113,no.6(February 12, 2009)
- ISSN：1520-5207
文摘
The encapsulation of 4242;,6-diamidino-2-phenylindole (DAPI) in the cucurbit[7]uril (CB7) cavity was studied by absorption, fluorescence, and NMR spectroscopic methods in aqueous solution. The profound change in the fluorescence characteristics was attributed to the formation of a very stable 1:1 inclusion complex. Three independent methods provided (1.1 ± 0.1) × 107 MW22;1 value for the binding constant. DAPI proved to be an excellent fluorescent probe for the investigation of the competitive binding of ionic liquids, surfactants, and biologically important compounds to CB7. The equilibrium constant of 1-alkyl-3-methylimidazolium inclusion was found to go through a maximum as the aliphatic chain length was increased, reaching the highest value for the hexyl derivative. The variation of the anion had a small effect. Among cationic surfactants containing a dodecyl tail, the stability of CB7 complex diminished with the growing hydrophobicity of the head group.