Synthesis of a Rigid C3v-Symmetric Tris-salicylaldehyde as a Precursor for a Highly Porous Molecular Cube

The development of a synthetic approach to a C3v‐symmetric tris‐salicylaldehyde based on triptycene is presented. The tris‐salicylaldehyde is a versatile precursor for porous molecular materials, as demonstrated in the [4+4] condensation reaction with a triptycene triamine to form a molecular shape‐persistent porous cube. The amorphous material of the molecular porous cube shows a very high surface area of 1014 m2 g−1 (BET model) and a high uptake of CO2 (18.2 wt % at 273 K and 1 bar). Furthermore, during the multistep synthesis of the tris‐salicylaldehyde precursor, a relatively rare (twofold) addition of the aryne to the anthracene in the 1,4‐ and 1,4,5,8‐positions have been found during a Diels–Alder reaction, as proven by X‐ray structure analysis. Get in shape! The synthesis of a shape‐persistent porous molecular organic cube through a [4+4] condensation is presented. The amorphous material has a specific BET surface area of 1014 m2 g−1 and shows an uptake of 18.4 wt % of CO2 (273 K, 1 bar) under ambient conditions with good Henry selectivities over N2.