Merchiori Sebastiano, Le Donne Andrea, Littlefair Josh D, Lowe Alexander Rowland, Yu Jiang-Jing, Wu Xu-Dong, Li Mian, Li Dan, Geppert-Rybczyńska Monika, Scheller Lukasz, Trump Benjamin A, Yakovenko Andrey A, Zajdel Paweł, Chorążewski Mirosław, Grosu Yaroslav, Meloni Simone
Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, 44121 Ferrara, Italy.
Institute of Chemistry, University of Silesia, Szkolna 9, 40-006 Katowice, Poland.
J Am Chem Soc. 2024 May 15;146(19):13236-13246. doi: 10.1021/jacs.4c01226. Epub 2024 May 3.
Fluids under extreme confinement show characteristics significantly different from those of their bulk counterpart. This work focuses on water confined within the complex cavities of highly hydrophobic metal-organic frameworks (MOFs) at high pressures. A combination of high-pressure intrusion-extrusion experiments with molecular dynamic simulations and synchrotron data reveals that supercritical transition for MOF-confined water takes place at a much lower temperature than in bulk water, ∼250 K below the reference values. This large shifting of the critical temperature () is attributed to the very large density of confined water vapor in the peculiar geometry and chemistry of the cavities of Cutebpz (tebpz = 3,3',5,5'-tetraethyl-4,4'-bipyrazolate) hydrophobic MOF. This is the first time the shift of is investigated for water confined within highly hydrophobic nanoporous materials, which explains why such a large reduction of the critical temperature was never reported before, neither experimentally nor computationally.
处于极端受限状态的流体表现出与它们的本体状态显著不同的特性。这项工作聚焦于在高压下被限制在高度疏水的金属有机框架（MOF）复杂孔洞内的水。高压侵入-挤出实验与分子动力学模拟以及同步加速器数据相结合，揭示出被MOF限制的水的超临界转变发生的温度比本体水低得多，比参考值低约250K。临界温度（）的这种大幅偏移归因于在Cutebpz（tebpz = 3,3',5,5'-四乙基-4,4'-联吡唑）疏水MOF孔洞独特的几何形状和化学性质中被限制的水蒸气具有非常大的密度。这是首次对被限制在高度疏水纳米多孔材料内的水的临界温度偏移进行研究，这解释了为什么之前从未有过关于临界温度如此大幅降低的实验或计算报道。
