端基含活性烯基的准轮烷的合成及表征--葫芦[6]脲与端烯基紫精的超分子自组装

Synthesis and Characterization of Pseudorotaxanes with Terminal Alkenyl Group——Supramolecular Self-assemblies of Cucurbit[6]uril and Alkenyl-terminated Viologen

通过葫芦[6]脲(CB[6])与端烯基紫精[N-正丁基-N'-(p-乙烯苄基)-4,4'-联吡啶盐,4VBVBu]在水溶液中于室温下进行超分子自组装,得到一种端基含活性烯基的水溶性紫精葫芦脲[2]准轮烷(4VBVBuCB),并通过1HNMR,IR,元素分析对其结构进行了表征,证实CB[6]位于4VBVBu端基的脂肪链上通过非共价键与4VBVBu结合,并且CB[6]与4VBVBu结合的物质的量之比为1∶1.热重分析(TGA)和紫外-可见吸收(UV-Vis)的结果证实了4VBVBuCB比4VBVBu有更高的热稳定性和UV-Vis吸收;盐效应结果表明NaI是4VBVBuCB优良的沉淀剂;环境扫描电镜(ESEM)证实4VBVBuCB比4VBVBu具有较强的刚性和较差的结晶能力.

A water soluble pseudorotaxane （4VBVBuCB） with an active terminal alkenyl group was synthesized by supramolecular self-assembly of cucurbit[6]uril （CB[6]） with alkenyl-terminated viologen [N-n-butyl-N＇-（p-vinylbenzyl）-4,4＇-bipyridinium bromide chloride, 4VBVBu] in water at room temperature. The chemical structures of 4VBVBu and 4VBVBuCB were confirmed by elemental analysis, ^1H NMR and IR spectra. CB[6] beads are localized on terminal aliphatic chain to combine N^＋of 4VBVBu by non-covalent bonds, and the molar ratio of CB[6] to 4VBVBu is 1 ： 1. The results of thermogravimetry analysis （TGA）, UV-Vis measurements show that 4VBVBuCB has higher thermal stability and stronger absorption band than 4VBVBu. The effect of salts on 4VBVBuCB was studied by the transmittance with UV-Vis, and the result shows that NaI is the satisfying precipitant to 4VBVBuCB. The microscopical morphologies of 4VBVBu and 4VBVBuCB were studied by environmental scanning electron microscopy （ESEM）, and the results show that 4VBVBuCB has higher rigidity and lower crystallizability than 4VBVBu.