Du Xinzhen, Chen Xiangchun, Lu Weihua, Hou Jinguo
Department of Chemistry, Chemistry and Chemical Engineering College, Northwest Normal University, Lanzhou 730070, PR China.
J Colloid Interface Sci. 2004 Jun 15;274(2):645-51. doi: 10.1016/j.jcis.2004.01.068.
The binding of polyethylene glycol (10) n-octylphenyl ether (OPE) and polyethylene glycol (10) tert-octylphenyl ether (Triton X-100, TX) to beta-cyclodextrin (beta-CD) and heptakis(2,3- beta-dimethyl)- beta-CD (DM- beta-CD) was described in detail by surface tension, steady-state fluorescence of OPE and TX, and phosphorescence of 1-bromonaphthalene (BN) probe. Surface tension and fluorescence measurements show that beta-CD entraps the hydrophobic moieties of OPE and TX to form inclusion complexes with the stoichiometry of 1:1. Unlike the n-octyl group of OPE, however, the tert-octyl group of TX fails to be encapsulated into the cavity of DM- beta-CD because of the steric hindrance of methyl groups at the rim of the cavity. The inclusion of the phenyl group of OPE and TX was demonstrated by dynamic quenching effect of iodide ion on fluorescence of OPE and TX in the presence of beta-CD. Static fluorescence quenching of OPE and TX by BN, phosphorescence of BN, and energy transfer between TX and BN provide additional evidence for the inclusion of their phenyl groups into the CD cavity. Analyses of molecular size suggest that the longer tert-octyl group of OPE is situated in curled manner in the cavity and the tert-octyl group of TX undergo a slight distortion for fit of beta-CD. Further introduction of the third guest component into the CD cavity occupied by OPE and TX will force the flexible octyl groups of OPE and TX to deform to a greater extent.
通过表面张力、聚乙二醇（10）正辛基苯基醚（OPE）和聚乙二醇（10）叔辛基苯基醚（Triton X - 100，TX）的稳态荧光以及1 - 溴萘（BN）探针的磷光，详细描述了聚乙二醇（10）正辛基苯基醚（OPE）和聚乙二醇（10）叔辛基苯基醚（TX）与β - 环糊精（β - CD）和七（2,3 - β - 二甲基）-β - 环糊精（DM - β - CD）的结合。表面张力和荧光测量表明，β - CD包埋OPE和TX的疏水部分，形成化学计量比为1:1的包合物。然而，与OPE的正辛基不同，TX的叔辛基由于空腔边缘甲基的空间位阻而未能被包封到DM - β - CD的空腔中。在β - CD存在下，碘离子对OPE和TX荧光的动态猝灭效应证明了OPE和TX苯基的包合。BN对OPE和TX的静态荧光猝灭、BN的磷光以及TX与BN之间的能量转移为它们的苯基包合到CD空腔中提供了额外证据。分子尺寸分析表明，OPE较长的叔辛基以卷曲方式位于空腔中，而TX的叔辛基为适应β - CD会发生轻微变形。将第三种客体组分进一步引入被OPE和TX占据的CD空腔中，将迫使OPE和TX的柔性辛基发生更大程度的变形。
