南京大学揭克诚研究小组近日取得一项新成果。他们通过海绵样大环晶体实现了分子挤压触发客体解吸附。2024年12月3日出版的《德国应用化学》发表了这项成果。

据介绍，传统多孔吸附剂的解吸通常采用，包括惰性气体吹扫、加热、真空处理在内的外力来触发客体实现释放。

研究组报道了一种在海绵状大环晶体中前所未有的，分子挤压触发的客体释放行为。晶体的功能就像典型的海绵一样，在其自适应形成的微观空隙中包含客体分子，可作为甲苯/吡啶分离的吸附剂。

有趣的是，蒸发的乙酸乙酯（ EA  ）分子会触发客体从晶体中释放出来，而不会进入晶体的孔隙或空隙来取代客体。相反，它们作为直接作用于晶体本身的外力，通过晶体表面上的大环和EA之间的超分子相互作用，“挤压”材料以关闭空隙，并释放客体分子。

各种实验技术和分子动力学模拟揭示了，分子挤压诱导客体释放过程的机理。EA再生晶体可以多次回收而不损失分离性能。与传统的客体释放工艺相比，该方法在温和的条件下操作，显示出节约成本和能源的潜力。

附：英文原文

Title: Molecular­­­–Squeeze Triggers Guest Desorption from Sponge–Like Macrocycle Crystals

Author: Kecheng Jie, Linnan Zhang, Lifeng Zheng, Yingying Song, Jingwei Huang, Hailong Ning, Leyong Wang, Jing Ma

Issue&Volume: 2024-12-03

Abstract: Desorption in conventional porous sorbents often employ external forces including inert gas blowing, heating, vacuum treatment to trigger guest release. We here report an unprecedented molecular–squeeze triggered guest release behavior from sponge–like macrocycle crystals. The crystals function as typical sponge to include guest molecules within their microscopic voids that are adaptively formed, thus acting as adsorbents for toluene/pyridine separations. Intriguingly, vaporized ethyl acetate (  EA  ) molecules trigger the guest release from the crystals without entering the pores or voids of the crystals to replace the guests. Instead, they work as external forces applied directly onto the crystals themselves, ‘‘squeezing” the materials to close the voids through supramolecular interactions between  EA  and macrocycles on the crystal surface and release the guest molecules. Various experimental techniques as well as molecular dynamics simulations reveal the mechanism of the molecular–squeeze induced guest release procedure. The  EA  –regenerated crystals can be recycled multiple times without the loss of separation performance. Compared with conventional guest release procedure, this method is manipulated in a mild condition, showing the potential in saving cost and energy.

DOI: 10.1002/anie.202420048

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202420048