Dual functionalized cages in metal-organic frameworks via stepwise postsynthetic modification

The introduction of bi- or multifunctionality into different cages of metal-organic frameworks (MOFs) has been of great interest because such MOF materials can demonstrate unique properties for various applications. Herein, we report a general strategy for creating different types of functionalized cages in MOFs by exerting control of the size of cage windows. Selective cage decoration was thereby enabled in such a manner that dual functional MOFs with different types of cages and pores can be created. The resultant different pore function MOF, DPF-MOF, is illustrated as a "proof of concept" in MOF MIL-101-Cr. An intermediate of a cascade reaction was successfully trapped and controlled the desired reaction direction. This DPF-MOF represents a new type of platform that, by trapping intermediates during the reaction processes, enhances our fundamental understanding of reaction chemistry in porous materials.