Supramolecular Proton Conductors Self-Assembled by Organic Cages

Yang, Zhenyu; Zhang, Ningjin; Lei, Lei; Yu, Chunyang; Ding, Junjie; Li, Pan; Chen, Jiaolong; Li, Ming; Ling, Sanliang; Zhuang, Xiaodong; Zhang, Shaodong

Abstract

Proton conduction is vital for living systems to execute various physiological activities. The understanding of its mechanism is also essential for the development of state-of-the-art applications, including fuel-cell technology. We herein present a bottom-up strategy, that is, the self-assembly of Cage-1 and -2 with an identical chemical composition but distinct structural features to provide two different supramolecular conductors that are ideal for the mechanistic study. Cage-1 with a larger cavity size and more H-bonding anchors self-assembled into a crystalline phase with more proton hopping pathways formed by H-bonding networks, where the proton conduction proceeded via the Grotthuss mechanism. Small cavity-sized Cage-2 with less H-bonding anchors formed the crystalline phase with loose channels filled with discrete H-bonding clusters, therefore allowing for the translational diffusion of protons, that is, vehicle mechanism. As a result, the former exhibited a proton conductivity of 1.59 × 10–4 S/cm at 303 K under a relative humidity of 48%, approximately 200-fold higher compared to that of the latter. Ab initio molecular dynamics simulations revealed distinct H-bonding dynamics in Cage-1 and -2, which provided further insights into potential proton diffusion mechanisms. This work therefore provides valuable guidelines for the rational design and search of novel proton-conducting materials.

Citation

Yang, Z., Zhang, N., Lei, L., Yu, C., Ding, J., Li, P., Chen, J., Li, M., Ling, S., Zhuang, X., & Zhang, S. (2022). Supramolecular Proton Conductors Self-Assembled by Organic Cages. JACS Au, 2(4), 819-826. https://doi.org/10.1021/jacsau.1c00556

• Journal Article Type: Article
• Acceptance Date: Mar 14, 2022
• Online Publication Date: Mar 21, 2022
• Publication Date: Apr 25, 2022
• Deposit Date: Mar 26, 2022
• Publicly Available Date: Mar 29, 2022
• Journal: JACS Au
• Print ISSN: 2691-3704
• Electronic ISSN: 2691-3704
• Publisher: American Chemical Society
• Peer Reviewed: Peer Reviewed
• Volume: 2
• Issue: 4
• Pages: 819-826
• DOI: https://doi.org/10.1021/jacsau.1c00556
• Public URL: https://nottingham-repository.worktribe.com/output/7655483
• Publisher URL: https://pubs.acs.org/doi/10.1021/jacsau.1c00556