Photoresponsive AA/BB supramolecular polymers comprising stiff-stilbene based guests and bispillar[5]arenes†
Abstract
We report the facile preparation of photoresponsive AA/BB supramolecular polymers comprising an E-stiff-stilbene bridged guest (E-G) and a disulfide-bridged bispillar[5]arene (H). The different assembly behaviours of Z-G and E-G with H were thoroughly investigated by 1H NMR, ROESY, DOSY and viscosity experiments, respectively. The 1 : 1 mixture of Z-G and H assembled into oligomers at 5–150 mM. In contrast, the 1 : 1 mixture of E-G and H assembled into AA/BB-type supramolecular polymers following a ring-chain polymerization mechanism. The formation and disassembly of the AA/BB supramolecular polymers were regulated by photoisomerization of stiff stilbene.