Switchable gate-opening effect in metal–organic polyhedra assemblies through solution processing† †Electronic supplementary information (ESI) available: Experimental procedures, crystallographic tables, thermogravimetric data, volumetric gas sorption data for N2 and CO2, additional powder X-ray diffraction data, and in situ powder X-ray diffraction-gas sorption experiments (PDF). X-ray crystallographic data in CIF format for 1-DMF, 1-THF, and 2-DMA. CCDC 1840858–1840860. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c8sc02263a

Assemblies of lantern-type metal–organic polyhedra are found to show gate-opening gas adsorption depending on how they are treated with solvents.
Gate-opening gas sorption is known for metal–organic frameworks, and is associated with structural flexibility and advantageous properties for sensing and gas uptake. Here, we show that gate-opening is also possible for metal–organic polyhedra (MOPs), and depends on the molecular organisation in the lattice. Thanks to the solubility of MOPs, several interchangeable solvatomorphs of a lantern-type MOP were synthesised via treatment with different solvents. One phase obtained through use of methanol induced a gate-opening effect in the lattice in response to carbon dioxide uptake. The sorption process was thoroughly investigated with in situ powder X-ray diffraction and simultaneous adsorption experiments. Meanwhile, solution processing of this flexible phase using THF led to a permanently porous phase without a gate-opening effect. Furthermore, we find that we can change the metallic composition of the MOP, and yet retain flexibility. By showing that gate-opening can be switched on and off depending on the solvent of crystallisation, these findings have implications for the solution-based processing of MOPs.