含两个识别点的侧链准聚轮烷的制备

合成了侧链含烷基链(C₇)及偶氮基团(Azo)两个疏水基团修饰的聚合物4,并基于环糊精与两个疏水基团C₇、Azo的不同结合能力,制备了含两个识别点的侧链准聚轮烷.首先,在聚合物4的溶液中加入α-环糊精(α-CD),α-CD分别包结在C₇及Azo部分,得到了侧链准聚轮烷;第二步,在365 nm的紫外光光照下,聚合物4侧链端基的trans-Azo异构为cis-Azo,α-CD从Azo部分解离,但α-CD仍包结在C₇部分,得到了侧链聚轮烷;第三步,在侧链聚轮烷溶液中加入β-环糊精(β-CD),β-CD包结在cis-Azo部分,得到了α-CD、β-CD分别包结两个疏水识别点的侧链准聚轮烷.

Preparation of Side-chain Polypseudorotaxane Bearing Two Recognition Sites

A polymer (44) bearing heptamethylene (C₇) and azobenzene (Azo) was synthesized. Based on the different association constants between the cyclodextrins and the hydrophobic moieties C₇ and Azo, a side-chain polypseudorotaxane was prepared. In the first step, α-cyclodextrin (α-CD) was added to the polymer 4 solution to form the side-chain polypseudorotaxane, in which the C₇ and Azo was both included by the α-CD. In the second step, the trans-Azo at the end of the side chain of the polymer 4 was isomerized to the cis-Azo under the irradiation of the 365 nm UV light to form the side-chain polyrotaxane, in which α-CD was interlocked on the side chain. In the final step, β-cyclodextrin (β-CD) was added to the side-chain polyrotaxane to form the side-chain polypseudorotaxane.