Self‐Assembly through Coordination and π‐Stacking: Controlled Switching of Circularly Polarized Luminescence

• Published in: Angewandte Chemie International Edition Vol. 58; no. 18; pp. 5946 - 5950
• Main Authors: Niu, Dian, Jiang, Yuqian, Ji, Lukang, Ouyang, Guanghui, Liu, Minghua
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 23.04.2019
• Edition: International ed. in English
• Subjects: Assembly; Chemical bonds; Chirality; Chromophores; Circular polarization; Histidine; Luminescence; Nanofibers; Nanospheres; noncovalent interactions; Pyrene; Stacking; supramolecular chemistry; Switching; zinc
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201900607

Multiple noncovalent interactions can drive self‐assembly through different pathways. Here, by coordination‐assisted changes in π‐stacking modes between chromophores in pyrene‐conjugated histidine (PyHis), a self‐assembly system with reversible and inversed switching of supramolecular chirality, as well as circularly polarized luminescence (CPL) is described. It was found that l‐PyHis self‐assembled into nanofibers showing P‐chirality and right‐handed CPL. Upon ZnII coordination, the nanofibers changed into nanospheres with M‐chirality, as well as left‐handed CPL. The process is reversible and the M‐chirality can change to P‐chirality by removing the ZnII ions. Experimental and theoretical models unequivocally revealed that the cooperation of metal coordination and π‐stacking modes are responsible the reversible switching of supramolecular chirality. This work not only provides insight into how multiple noncovalent interactions regulate self‐assembly pathways. Chirality switch: By efficiently switching the π‐stacking modes, T‐shaped and π–π stacking, of pyrenes by zinc coordination, a dynamic supramolecular system is obtained. The system allows control in the change of circularly polarized luminescence (CPL) and is reversible.