Doubly, Triply and Multiply Pleated Sheets of Bipyridinium Radical Cation-Incorporated Polymers Tuned by Four Cucurbiturils

作者：Qi, Qi; Yang, Bo; Xi, Cheng-Gang; Yang, Xiran; Zhang, Dan-Wei^*; Liu, Simin^*; Li, Zhan-Ting^*

来源：ChemistrySelect, 2016, 1(21): 6792-6796.

DOI：10.1002/slct.201601760

• bipyridinium
• cucurbit[n]uril
• foldamer
• pleated sheet
• radical cation dimerization

Depending on the size of their cavity, cucurbit[n]urils (CB[n], n= 5, 7, 8, and 10) exhibit very different encapsulation selectivity. This feature has been utilized to tune the formation and switching of three kinds of pleated sheets of bipyridinium radical cation (BIPY center dot+)-based polymers in water. Driven by the dimerization of the BIPY center dot+ units, the polymers spontaneously form multiply pleated sheets. These pleated foldamers can be reversibly converted into flexible pseudopoly-rotaxanes, doubly and triply pleated sheets by CB[7], CB[8] and CB[10], respectively, through selective encapsulation of the macrocycles for one, two or three stacked BIPY center dot+ units. Adding adamantamonium (ADMT), hexamethylenetetramine (HMTA) or CB[5] to the respective solutions leads to taking away of the CB rings from the polymers due to the formation of more stable 1: 1 complexes and as a result, multiply pleated sheets are recovered. UV-vis absorption spectroscopy has been used to investigate the formation and conversion of the pleated and extended states of the polymers.

• 出版日期2016-12-16
• 单位复旦大学; 武汉科技大学