Reversible adsorption and separation of volatile aromatics based on a porous Cd( ii ) MOF

A series of isostructual aromatics⊂CdL2(OTs)2 (aromatics = benzene, toluene, o-xylene, m-xylene and p-xylene) supramolecular complexes were prepared based on aromatic templates. The CdL2(OTs)2 framework is stable and contains square-like hydrophobic channels. It can reversibly adsorb benzene, toluene, o-xylene, m-xylene and p-xylene in the liquid phase without the loss of its structural integrity. Furthermore, it exhibits a clear affinity for these aromatics according to the following order: xylene > toluene > benzene, and it effectively separates xylene/toluene/benzene mixtures in the liquid phase under ambient conditions. In addition, aromatics⊂CdL2(OTs)2 exhibits guest-dependent luminescence properties.