Charge-transfer complexation of coordination cages for enhanced photochromism and photocatalysis

Li, Gen; Du, Zelin; Wu, Chao; Liu, Yawei; Xu, Yan; Lavendomme, Roy; Liang, Shihang; Gao, En-Qing; Zhang, Dawei

Abstract

Intensified host-guest electronic interplay within stable metal-organic cages (MOCs) presents great opportunities for applications in stimuli response and photocatalysis. Zr-MOCs represent a type of robust discrete hosts for such a design, but their host-guest chemistry in solution is hampered by the limited solubility. Here, by using pyridinium-derived cationic ligands with tetrakis(3,5-bis(trifluoromethyl)phenyl)borate (BArF−) as solubilizing counteranions, we report the preparation of soluble Zr-MOCs of different shapes (1-4) that are otherwise inaccessible through a conventional method. Enforced arrangement of the multiple electron-deficient pyridinium groups into one cage (1) leads to magnified positive electrostatic field and electron-accepting strength in favor of hosting electron-donating anions, including halides and tetraarylborates. The strong charge-transfer (CT) interactions activate guest-to-host photoinduced electron transfer (PET), leading to pronounced and regulable photochromisms. Both ground-state and radical structures of host and host-guest complexes have been unambiguously characterized by X-ray crystallography. The CT-enhanced PET also enables the use of 1 as an efficient photocatalyst for aerobic oxidation of tetraarylborates into biaryls and phenols. This work presents the solution assembly of soluble Zr-MOCs from cationic ligands with the assistance of solubilizing anions and highlights the great potential of harnessing host-guest CT for boosting PET-based functions and applications.

Citation

Li, G., Du, Z., Wu, C., Liu, Y., Xu, Y., Lavendomme, R., Liang, S., Gao, E.-Q., & Zhang, D. (2025). Charge-transfer complexation of coordination cages for enhanced photochromism and photocatalysis. Nature Communications, 16(1), Article 546. https://doi.org/10.1038/s41467-025-55893-z

• Journal Article Type: Article
• Acceptance Date: Jan 2, 2025
• Online Publication Date: Jan 9, 2025
• Publication Date: Jan 9, 2025
• Deposit Date: Feb 5, 2025
• Publicly Available Date: Feb 5, 2025
• Journal: Nature Communications
• Electronic ISSN: 2041-1723
• Publisher: Nature Research
• Peer Reviewed: Peer Reviewed
• Volume: 16
• Issue: 1
• Article Number: 546
• DOI: https://doi.org/10.1038/s41467-025-55893-z
• Public URL: https://durham-repository.worktribe.com/output/3341826