State Key Laboratory of Luminescent Materials and Devices, Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou, P. R. China.
Institute for Integrated Cell-Material Sciences, Institute for Advanced Study, Kyoto University, Kyoto, Japan.
Nature. 2022 Nov;611(7935):289-294. doi: 10.1038/s41586-022-05310-y. Epub 2022 Nov 9.
The discovery of a method to separate isotopologues, molecular entities that differ in only isotopic composition, is fundamentally and technologically essential but remains challenging. Water isotopologues, which are very important in biological processes, industry, medical care, etc. are among the most difficult isotopologue pairs to separate because of their very similar physicochemical properties and chemical exchange equilibrium. Herein, we report efficient separation of water isotopologues at room temperature by constructing two porous coordination polymers (PCPs, or metal-organic frameworks) in which flip-flop molecular motions within the frameworks provide diffusion-regulatory functionality. Guest traffic is regulated by the local motions of dynamic gates on contracted pore apertures, thereby amplifying the slight differences in the diffusion rates of water isotopologues. Significant temperature-responsive adsorption occurs on both PCPs: HO vapour is preferentially adsorbed into the PCPs, with substantially increased uptake compared to that of DO vapour, facilitating kinetics-based vapour separation of HO/HDO/DO ternary mixtures with high HO separation factors of around 210 at room temperature.
发现一种分离同位素的方法对于仅在同位素组成上存在差异的分子实体至关重要，从根本上和技术上来说都是必要的，但仍然具有挑战性。水的同位素对在生物过程、工业、医疗保健等方面非常重要，由于它们非常相似的物理化学性质和化学交换平衡，是最难分离的同位素对之一。在此，我们通过构建两种在室温下有效分离水同位素的多孔配位聚合物（PCP，或金属-有机骨架）来报告这一发现，其中框架内的翻转分子运动为扩散调节功能提供了支持。通过收缩孔口上动态门的局部运动来调节客体流量，从而放大了水同位素扩散率的微小差异。两种 PCP 都表现出显著的温度响应吸附：HO 蒸汽优先被吸附到 PCP 中，与 DO 蒸汽相比，其吸附量大大增加，从而促进了基于动力学的 HO/HDO/DO 三元混合物的蒸汽分离，在室温下，HO 的分离因子高达 210 左右。
