日本东北大学宫坂等（Hitoshi Miyasaka）研究团队发现了一种能通过改变顺磁-铁磁性感知二氧化碳（CO₂）的金属有机框架（MOF）材料。相关论文发表在2020年11月30日出版的《自然—化学》杂志上。

在该研究中，课题组报道了一种CO₂响应的磁性MOF，该材料能在CO₂吸附时由铁磁性转变为顺磁性，并在CO₂解吸时回到铁磁性状态。这种铁磁性材料是一种有着[D⁺-A^--D]形式的层状MOF，该MOF合成时以三氟苯甲酸桥联的桨叶型二钌(II)团簇作为电子供体（D），并以双乙氧基四氰醌二甲烷作为电子受体（A）。该材料在吸收二氧化碳后，通过平面内电子转移和结构变化采取了一种[D-A-D]的顺磁构型。

进一步研究表明，这种磁相变和随之而来的MOF电导率和电容率的变化，被镶嵌在框架中的客体CO₂分子通过电子效应稳定着。

据了解，在有充足可选模块的前提下，MOF材料可以将多孔性和磁有序性结合在一起。取决于孔道中的客体分子存在与否，MOF可以表现出非常不同的磁性特征，这使得MOF材料成为了一个开发能响应外部刺激的材料的有前途的平台，在气体的储存检测一体化等方面有着重要的应用潜力。

附：英文原文

Title: A metal–organic framework that exhibits CO 2 -induced transitions between paramagnetism and ferrimagnetism

Author: Jun Zhang, Wataru Kosaka, Yasutaka Kitagawa, Hitoshi Miyasaka

Issue&Volume: 2020-11-30

Abstract: With adequate building blocks, metal–organic frameworks (MOFs) can combine magnetic ordering and porosity. This makes MOFs a promising platform for the development of stimuli-responsive materials that show drastically different magnetic properties depending on the presence or absence of guest molecules within their pores. Here we report a CO2-responsive magnetic MOF that converts from ferrimagnetic to paramagnetic on CO2 adsorption, and returns to the ferrimagnetic state on CO2 desorption. The ferrimagnetic material is a layered MOF with a [D+–A–D] formula, produced from the reaction of trifluorobenzoate-bridged paddlewheel-type diruthenium(II) clusters as the electron donor (D) with diethoxytetracyanoquinodimethane as the electron acceptor (A). On CO2 uptake, it undergoes an in-plane electron transfer and a structural transition to adopt a [D–A–D] paramagnetic form. This magnetic phase change, and the accompanying modifications to the electronic conductivity and permittivity of the MOF, are electronically stabilized by the guest CO2 molecules accommodated in the framework.

DOI: 10.1038/s41557-020-00577-y

Source: https://www.nature.com/articles/s41557-020-00577-y