In this work, we present a case system that can achieve rapid structural rearrangement of the whole lattice of a metal–organic framework (MOF) through a ‘domino’ alteration of the bond connectivity under mild conditions. Topological transitions between significantly different phases typically require extreme conditions to collectively break chemical bonds and overcome the stress caused to the original structure by altering its correlated bond environment.
Our system transforms from a disordered and less crystalline MOF (AlTz-53) with low porosity to a highly crystalline and porous isomer (AlTz-68) within few minutes upon activation (solvent exchange and desorption), resulting in a significant increase in surface area, from 725 to 2,749 m2/g. Spectroscopic measurements show that this counter-intuitive lattice rearrangement involves a metastable intermediate with defect frameworks that results from solvent removal on coordinately unsaturated metal sites. This less crystalline–crystalline switch between two topological distinct MOFs is shown to be reversible over four cycles through activation and re-immersion in polar solvents.
