The encapsulation of photoactive guests into a metal-organic framework is advantageous in endowing extra functionalities such as photochromism and photoswitchable luminescence. In this paper, a host-guest MOF material, [Zn₃(IPA)₄ ​MV] (1) (H₂IPA ​= ​isophthalic acid, MV·2NO₃ ​= ​1,1'-dimethyl-(4,4'-bipyridine)-1,1'-diium dinitrate) has been constructed by encapsulating simplest methyl viologen guest into the anionic MOF framework. This material exhibits reversible naked-eye detectable photochromic properties varying from colorless to blue upon UV–Vis light irradiation. The MV²⁺ and the short O⋯N distance between the oxygen atom and pyridine ring of MV²⁺ play a crucial role in the photochromism of this compound. This host-guest MOF compound shows photoswitchable luminescent properties in the solid state. More interestingly, this host-guest MOF material can be deposited on filter paper and can be employed as inkless print material by controlling the UV–Vis light irradiation with the stencil.

将光活性客体封装在金属有机框架中有利于赋予额外的功能，如光致变色和光可切换发光。本文采用一种主客体MOF材料，[Zn ₃ (IPA) ₄  MV] ( 1 ) (H ₂ IPA = 间苯二甲酸，MV·2NO ₃  = 1,1'-二甲基-(4 ,4'-联吡啶)-1,1'-二硝酸二鎓)是通过将最简单的甲基紫精客体封装到阴离子 MOF 框架中构建的。这种材料在紫外-可见光照射下表现出可逆的肉眼可检测的光致变色特性，从无色到蓝色。的MV ²⁺和短Ó⋯氧原子和MV的吡啶环之间的N个距离²⁺在该化合物的光致变色中起关键作用。这种主客体 MOF 化合物在固态下显示出光可开关的发光特性。更有趣的是，这种主客体 MOF 材料可以沉积在滤纸上，并且可以通过控制模板的 UV-Vis 光照射用作无墨印刷材料。