Yang Fan, Kong Xiang-Jing, He Tao, Zhang Zhengqing, Wang Ke, Du Honglin, Cai Guohong, Ju Jing, Wang Xiaoge, Li Jian-Rong, Sun Junliang, Zhong Chongli
State Key Laboratory of Advanced Separation Membrane Materials, School of Chemistry and Chemical Engineering, Tiangong University Tianjin 300387 P. R. China
Beijing Key Laboratory for Green Catalysis and Separation and Department of Chemical Engineering, College of Materials Science and Engineering, Beijing University of Technology Beijing China
Chem Sci. 2025 May 31;16(26):11823-11832. doi: 10.1039/d5sc03014e. eCollection 2025 Jul 2.
Constructing sulfonate coordination polymers (CPs) with high stability remains a significant challenge due to the relatively weak coordination ability of the sulfonate group, especially when paired with highly inert Cr ions. In this study, we designed solvent-free methods to enhance Cr(iii)-sulfonate coordination and further advance its reticular chemistry. For the first time, two Cr(iii)-sulfonate CPs, TGU-9 and TGU-10, were successfully constructed, along with two supramolecules, TGU-7 and TGU-8. All structures were elucidated using the 3D electron diffraction technique. Through solvent-free methods, Cr(iii)-sulfonate coordination was achieved by a double displacement reaction between Cr salts and -SOH groups. In particular, this method resulted in a counterintuitive coordination reversal from -COO > -SO to -SO > -COO. Reaction mechanism analysis revealed that the higher acidity of the -SOH group, compared to the -COOH group, leads to its preferential deprotonation, thereby facilitating the kinetics of Cr-sulfonate self-assembly. Furthermore, both TGU-9 and TGU-10 exhibited exceptional long-term stability under ambient conditions and over a wide pH range. They also showed high proton conductivity exceeding 10 S cm, ranking in the top two among the reported sulfonate CPs. The designed solvent-free method demonstrated a generally applicable and simple strategy in designing novel metal-ligand coordination and constructing reticular chemistry, beyond the limitations of conventional solvent-based methods.
由于磺酸根基团的配位能力相对较弱，构建具有高稳定性的磺酸根配位聚合物（CPs）仍然是一项重大挑战，尤其是当与高度惰性的铬离子配对时。在本研究中，我们设计了无溶剂方法来增强Cr(iii)-磺酸根配位，并进一步推进其网状化学。首次成功构建了两种Cr(iii)-磺酸根CPs，即TGU-9和TGU-10，以及两种超分子，即TGU-7和TGU-8。所有结构均使用3D电子衍射技术进行了阐明。通过无溶剂方法，Cr(iii)-磺酸根配位是通过Cr盐与-SOH基团之间的双置换反应实现的。特别是，这种方法导致了一种与直觉相反的配位反转，从-COO > -SO转变为-SO > -COO。反应机理分析表明，-SOH基团比-COOH基团具有更高的酸度，导致其优先去质子化，从而促进了Cr-磺酸根自组装的动力学。此外，TGU-9和TGU-10在环境条件下和较宽的pH范围内均表现出优异的长期稳定性。它们还显示出超过10 S cm的高质子传导率，在已报道的磺酸根CPs中排名前两位。所设计的无溶剂方法展示了一种通用且简单的策略，可用于设计新型金属-配体配位和构建网状化学，突破了传统溶剂法的限制。
