MOCOFs: Crystalline porous frameworks based on double extension of metal–organic and covalent organic linkages

Reticular chemistry is a powerful strategy to design solid materials with fine-tuned chemical functionality and porosity, such as metal–organic frameworks (MOFs) and covalent organic frameworks (COFs). While MOFs typically show high crystallinity due to their highly reversible coordinative bonds, the organic backbone of COFs provides high chemical stability. Here, we combine the best of both worlds by introducing metal–organic–covalent–organic frameworks (MOCOFs), a new class of reticular materials through the double extension of metal–organic and covalent organic linkages. Several MOCOFs are obtained by the reactions between a cobalt aminoporphyrin and dialdehydes, which are interconnected by cobalt–amine coordination and imine condensation to form 3D networks. The MOCOFs show an unprecedented chiral topological net, large surface area, high crystallinity, and chemical stability owing to the two types of extended linkages. Thus, MOCOFs present a new reticular design strategy that further diversifies the chemical and structural space of porous solids.