分⼦を識別し、⾊・⼤きさ・硬さが変わる多孔性ゲル

2026-05-22 京都⼤学アイセムス

MOPEGゲルのメカニズム：バスケットボールのゴールネットに見立てたポリマーのネットワークが、バスケットボールに見立てた特定の分子標的を捕捉することで、材料の色や形などの見た目が変化する。

＜関連情報＞

• https://www.icems.kyoto-u.ac.jp/news/11476/
• https://pubs.acs.org/doi/10.1021/jacs.6c06620

配位ゲスト認識が共有結合した金属有機多面体ポリマーゲルの巨視的変形を引き起こす Coordinative Guest Recognition Triggers Macroscale Deformation of Covalently Linked Metal–Organic Polyhedra Polymer Gels

Tomoki Tateishi,Shunsuke Imai,Ayana Miyata,Yuki Tokudome,Kenji Urayama,and Shuhei Furukawa
Journal of the American Chemical Society  Published: May 4, 2026
DOI: https://doi.org/10.1021/jacs.6c06620

Abstract

Molecular recognition plays a central role in supramolecular chemistry. The concept of molecular recognition initially emerged from discrete molecular systems and has now been expanded to solid-state soft materials; however, there remains a lack of knowledge to elucidate the relationship between molecular recognition events and the modulation of macroscale properties. Here, we present a new type of polymer gel that discriminates structurally similar guests by utilizing coordination interactions. Our approach uses Rh(II)-based metal–organic polyhedra (MOPs) as both coordinative recognition sites and cross-linking nodes. By connecting MOPs with flexible, deformable poly(ethylene glycol)s, covalently linked MOP polymer gels are formed while preserving accessible coordination sites. The resulting MOP polymer gels exhibit macroscale shrinkage and swelling behavior in response to solvent exchange and guest molecule recognition. Specifically, ditopic coordinative guests induce significant gel shrinkage, whereas a structurally similar noncoordinative guest results in negligible volumetric changes. This difference highlights the capability of the MOP polymer gel to distinguish subtle structural differences of the guests at the coordinative recognition sites and to propagate the recognition events into macroscale shrinkage. Correspondingly, the storage modulus of the gel increases upon guest-induced shrinkage, which indicates that coordinative guest recognition reinforces the polymer network within the gel. These results establish a correlation between coordinative guest recognition and macroscale changes in the volumetric deformation and mechanical properties of the gels. This covalently linked MOP polymer gel system paves the way for designing stimuli-responsive, functional soft materials.