中国科学院物理研究所陈小龙研究团队揭示了有机-无机超晶格中氢键的动态到静态转换引起了金属-绝缘体的转变。相关研究成果发表在2024年8月14日出版的《自然—化学》。

氢键深刻地影响着分子和材料的基本化学、物理和生物性质。由于与其他化学键相比，氢键的相互作用相对较弱，因此仅靠氢键通常不足以引起电性能的实质性变化，从而对它们在相关器件中的应用施加了严重的限制。

该文中，研究人员报告了一种由氢键控制的有机-无机（1,3-丙二胺）_0.5SnSe₂超晶格的金属-绝缘体转变，该超晶格的电阻率为10⁷，具有巨大的开关比。诱导转变的关键是氨基氢键结构从动态到静态的变化。

在动态下，热激活的自由旋转不断断裂，并与相邻的硒阴离子形成瞬态氢键。在静态下，氨基形成三个固定角度的位置，每个位置相隔120°。

该发现有助于理解有机-无机杂化材料中的电现象，并可用于未来基于分子的电子材料的设计。

附：英文原文

Title: Dynamic-to-static switch of hydrogen bonds induces a metal–insulator transition in an organic–inorganic superlattice

Author: Xie, Zhenkai, Luo, Rui, Ying, Tianping, Gao, Yurui, Song, Boqin, Yu, Tongxu, Chen, Xu, Hao, Munan, Chai, Congcong, Yan, Jiashu, Huang, Zhiheng, Chen, Zhiguo, Du, Luojun, Zhu, Chongqin, Guo, Jiangang, Chen, Xiaolong

Issue&Volume: 2024-08-14

Abstract: Hydrogen bonds profoundly influence the fundamental chemical, physical and biological properties of molecules and materials. Owing to their relatively weaker interactions compared to other chemical bonds, hydrogen bonds alone are generally insufficient to induce substantial changes in electrical properties, thus imposing severe constraints on their applications in related devices. Here we report a metal–insulator transition controlled by hydrogen bonds for an organic–inorganic (1,3-diaminopropane)0.5SnSe2 superlattice that exhibits a colossal on–off ratio of 107 in electrical resistivity. The key to inducing the transition is a change in the amino group’s hydrogen-bonding structure from dynamic to static. In the dynamic state, thermally activated free rotation continuously breaks and forms transient hydrogen bonds with adjacent Se anions. In the static state, the amino group forms three fixed-angle positions, each separated by 120°. Our findings contribute to the understanding of electrical phenomena in organic–inorganic hybrid materials and may be used for the design of future molecule-based electronic materials.

DOI: 10.1038/s41557-024-01566-1

Source: https://www.nature.com/articles/s41557-024-01566-1