Pore engineering of metal-organic frameworks: introduction of chemically accessible Lewis basic sites inside MOF channels

This paper highlights recent developments of functional metal-organic frameworks (MOFs), especially with Lewis basic motifs inside MOF channels. To endow MOFs with special functionalities and properties, various attempts in pore engineering have been made to functionalize the channels by introducing chemically accessible Lewis basic sites. The Lewis basic sites inside the confined MOF channels are beneficial for CO2 adsorption, selective catalytic organic transformations, and the capture of biologically important species. We classified three different main Lewis basic motifs for pore engineering of MOFs: (i) carboxy-based Lewis basic ligands; (ii) N-containing aromatic ring-based Lewis basic ligands; and (iii) other N-containing Lewis basic ligands. All of these examples establish MOFs as a new class of crystalline porous material suitable for a wide range of applications that are important in both academia and industry.