化学学报 ›› 2007, Vol. 65 ›› Issue (11): 1076-1080. 上一篇    下一篇

研究论文

三嗪基苯胺桥联双环糊精的合成及其对染料分子的选择键合

陈湧, 韩宁, 杨华, 刘育*   

  1. (南开大学化学系元素有机化学国家重点实验室 天津 300071)
  • 投稿日期:2006-09-25 修回日期:2006-12-08 发布日期:2007-06-14
  • 通讯作者: 刘育

Synthesis of Triazinylanilino-bridged Bis(β-cyclodextrin)s and Their Selective Binding Behaviors with Dyes

CHEN Yong; HAN Ning; YANG Hua; LIU Yu*   

  1. (Department of Chemistry, State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071)
  • Received:2006-09-25 Revised:2006-12-08 Published:2007-06-14
  • Contact: LIU Yu

通过N,N-二乙基-4-(二氯代-1,3,5-三嗪-2-基)苯胺分别与单-[6-(乙二胺基)-6-脱氧]-β-环糊精和单-[6-(二乙烯三胺基)-6-脱氧]-β-环糊精反应合成了两种三嗪基苯胺桥联双环糊精, 采用荧光和紫外光谱滴定方法测定了它们在磷酸缓冲溶液中(25 ℃, pH=7.2)与几种具有不同形状和电子密度的染料分子包结配位的稳定常数. 结果表明, 三嗪基苯胺桥联双环糊精不但对具有较大电子密度的三角形客体结晶紫给出了6~26倍于天然环糊精的配位稳定常数, 而且对结晶紫/中性红分子对给出了高的分子选择性(KCV/KNR23~31). 分子力学研究表明, 桥联双环糊精对客体分子的强键合能力主要源于两个环糊精空腔及桥链基团对客体分子的协同键合, 特别是桥链中三嗪基苯胺基团与客体之间的p-p相互作用.

关键词: 桥联双环糊精, 染料, 光谱滴定, 协同键合, p-p相互作用

Two triazinylanilino-bridged bis(β-cyclodextrin)s were synthesized by the reactions of N,N-diethyl-4-(4,6-dichloro-1,3,5-triazin-2-yl)aniline with 6-ethylenediamino-6-deoxy-β-cyclodextrin and 6-diethylenetriamino-6-deoxy-β-cyclodextrin. The complex stability constants for the inclusion complexation of these bis(β-cyclodextrin)s with several dyes possessing different shapes and electron intensities were determined by means of fluorescence and UV-Vis titrations at 25 ℃ in phosphate buffer solution (pH 7.2). The results show that the triazinylanilino-bridged bis(β-cyclodextrin)s exhibit not only the high complex stability constants, i.e. 6~26 times higher than that of native β-cyclodextrin, for triangular guest crystal violent that possesses a larger electron intensity, but also the high molecular selectivity for crystal violent/neutral red pair (KCV/KNR23~31). Molecular dynamics studies show that the strong binding ability of triazinylanilino-bridged bis(β-cyclodextrin)s can be mainly attributed to the cooperative binding of two cyclodextrin cavities and the bridge chain, especially the p-p interactions between the triazinylaniline group in the bridge chain and the guest dye.

Key words: bridged bis(b-cyclodextrin), dye, spectral titration, cooperative binding, p-p interaction