Ma Nattapol, Ohtani Ryo, Le Hung M, Sørensen Søren S, Ishikawa Ryuta, Kawata Satoshi, Bureekaew Sareeya, Kosasang Soracha, Kawazoe Yoshiyuki, Ohara Koji, Smedskjaer Morten M, Horike Satoshi
Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto, 615-8510, Japan.
Department of Chemistry, Faculty of Science, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan.
Nat Commun. 2022 Jul 12;13(1):4023. doi: 10.1038/s41467-022-31658-w.
Prussian blue analogues (PBAs) are archetypes of microporous coordination polymers/metal-organic frameworks whose versatile composition allows for diverse functionalities. However, developments in PBAs have centred solely on their crystalline state, and the glassy state of PBAs has not been explored. Here we describe the preparation of the glassy state of PBAs via a mechanically induced crystal-to-glass transformation and explore their properties. The preservation of short-range metal-ligand-metal connectivity is confirmed, enabling the framework-based functionality and semiconductivity in the glass. The transformation also generates unconventional CN vacancies, followed by the reduction of metal sites. This leads to significant porosity enhancement in recrystallised PBA, enabled by further accessibility of isolated micropores. Finally, mechanical stability under stress for successful vitrification is correlated to defect contents and interstitial water. Our results demonstrate how mechanochemistry provides opportunities to explore glassy states of molecular framework materials in which the stable liquid state is absent.
普鲁士蓝类似物（PBAs）是微孔配位聚合物/金属有机框架的原型，其多样的组成赋予了多种功能。然而，PBAs的发展仅集中在其晶体状态，而PBAs的玻璃态尚未得到探索。在此，我们描述了通过机械诱导的晶体到玻璃的转变制备PBAs玻璃态的方法，并探索了它们的性质。短程金属-配体-金属连接性得以保留，使玻璃中基于框架的功能和半导体性成为可能。这种转变还产生了非常规的氰基空位，随后金属位点减少。这导致重结晶的PBA中孔隙率显著提高，这是由于孤立微孔的进一步可及性所致。最后，成功玻璃化所需的应力下的机械稳定性与缺陷含量和间隙水相关。我们的结果表明了机械化学如何为探索不存在稳定液态的分子框架材料的玻璃态提供机会。
