Ionic Hydrogen‐Bonded Organic Frameworks: A New Type of Porous Organic Solid Base

• Published in: Angewandte Chemie Vol. 137; no. 38
• Main Authors: Hou, Ying, Fang, Han‐Ru, Li, Yu‐Lin, Zhang, An‐An, Huang, Xin‐Song, Cai, Lei, Yin, Qi, Wang, Rui, Li, Jin‐Lin, Liu, Tian‐Fu
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 15.09.2025
• Subjects: Acid-base neutralization; Base catalysis; Basicity; Chemical reactions; Crystal transformation; Crystallinity; Hydrogen bonding; Hydrogen‐bonded organic frameworks; Interfacial properties; Modular structures; Neutralization; Organic solid base; Porosity; Structure transformation; X-ray diffraction
• ISSN: 0044-8249; 1521-3757
• DOI: 10.1002/ange.202510614

Solid base offers advantages in terms of the ease of handling, environmentally sustainable processes, and tunable interfacial properties. Despite of these benefits, the exploration of new solid bases remains challenging and is an underdeveloped area of research. In this work, we report the discovery of the inherent basicity of hydrogen‐bonded organic frameworks (HOFs). The high crystallinity of HOFs enables us to monitor the precise structure changes and proton transfer process during acid‐base neutralization reaction through single‐crystal X‐ray diffraction. With this information, the origin of basicity and the underlying mechanism can be identified, which further guide us to discover other porous solid bases and unveil the universal characteristic of some anionic HOFs. The practical use of the porous solid bases was demonstrated by base‐catalyzed reactions, exhibiting high activity and selectivity. This study enriches the solid‐base family by introducing a type of materials featured with high porosity, high crystallinity, and modular structure. Solid bases are important reagents widely used in both fundamental research and industry applications. Here, we developed a new type of porous organic solid base via self‐assembly of deprotonated monomers. The basicity was confirmed by in situ DRIFTS and measured by titration, while the proton‐induced structural transformation was clearly revealed by single‐crystal X‐ray diffraction. The abundant basic sites and inherent porosity make solid bases as a new type of catalysts with excellent catalytic activity.