Melt-quenched glass formation of a family of metal-carboxylate frameworks
Wen‐Long Xue, G. Li, Hui Chen, Yuchen Han, Feng Li, Lu Wang, Xiao-Ling Gu, Si-Yuan Hu, Yu‐Heng Deng, Lei Tan, Martin T. Dove, Wei Li, Jiangwei Zhang, Hongliang Dong, Zhiqiang Chen, Weihua Deng, Gang Xu, Wang Guo, Chong‐Qing Wan
Abstract
Metal-organic framework (MOF) glasses are an emerging class of glasses which complement traditional inorganic, organic and metallic counterparts due to their hybrid nature. Although a few zeolitic imidazolate frameworks have been made into glasses, how to melt and quench the largest subclass of MOFs, metal carboxylate frameworks, into glasses remains challenging. Here, we develop a strategy by grafting the zwitterions on the carboxylate ligands and incorporating organic acids in the framework channels to enable the glass formation. The charge delocalization of zwitterion-acid subsystem and the densely filled channels facilitate the coordination bonding mismatch and thus reduce the melting temperature. Following melt-quenching realizes the glass formation of a family of carboxylate MOFs (UiO-67, UiO-68 and DUT-5), which are usually believed to be un-meltable. Our work opens up an avenue for melt-quenching porous molecular solids into glasses.