Metal organic frameworks from extended, conjugated pentiptycene-based ligands

Two new conjugated, iptycene-containing, organic proligands were synthesized for incorporation into zinc-containing metal-organic frameworks (MOFs). A 2D pentiptycene-containing, square-paddlewheel MOF was first synthesized and characterized. By varying the reaction conditions slightly, the capping ligand could be changed, but the long-range order and packing of the 2D sheets was not altered. Addition of 4,4'-bipyridine allowed the deliberate synthesis of a 3D pillared MOF. The crystal structure of this material shows very large void spaces, but solvent-exchange and evacuation led to the collapse of the structure and a loss of crystallinity. This work demonstrates the potential to achieve high porosity by preparing MOFs from iptycene-containing ligands.