Construction of Photo‐Responsive Pd2L4‐Type Nanocages based on Feringa's Second‐Generation Motor and Its Guest Binding Ability for C60

• Published in: Chemistry : a European journal Vol. 28; no. 59
• Main Authors: Qin, Yunan, Xiong, Jingpeng, Li, Quan, Zhang, Yuexing, Zeng, Ming‐Hua
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 21.10.2022
• Subjects: adaptivity; Buckminsterfullerene; Cages; Chemistry; Encapsulation; guest encapsulation; metal-organic cage; Molecular dynamics; molecular motor; Molecular motors; Molecular structure; NMR; Nuclear magnetic resonance; photoresponsiveness
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.202201821

We present the construction of a M2L4‐type metal‐organic nanocage featuring four endohedral Feringa's motor motifs and its adaptive encapsulation towards a C60 guest molecule. The structure of the cage, though complicated on the 1H NMR spectrum due to the adoption of mixed ligands, was unambiguously characterized with a combination of ESI‐MS, 2D DOSY, 13C NMR and particularly the SAXS technique. The molecular motor within the cage demonstrated similar photophysical properties to the uncoordinated one, indicating the motor's function was not compromised when it was anchored in such a confined nanospace. Furthermore, the nanocage showed good guest encapsulation ability towards C60, and a guest induced‐fit behavior of the cage was revealed based on the extensive SAXS analysis and molecular dynamics simulation. The adaptive motorized nanocage reported here represents one of the very few examples of integrating individual motors into a discrete nanoconfined system and offers prospects to achieve its non‐equilibrium functions. A novel banana‐shaped and bis‐monodentate ligand based on Feringa's second‐generation molecular motor was designed and synthesized. Subsequently, a M2L4‐type metal‐organic nanocage featuring four endohedral motor motifs was constructed by reacting stoichiometric motor ligand with Pd2+. This motorized nanocage showed good guest encapsulation ability towards C60, offering prospects as a prototype of “motor factory” to achieve the motor's non‐equilibrium functions.