Synthesis and Properties of (Triptycenedicarboxylatio)zinc Coordination Networks

Paddle wheels and pillars: Layered 3D metal–organic frameworks comprised of paddle-wheel coordination units are constructed under a variety of conditions to incorporate bridging ligands (as illustrated) that impart desired properties, such as guest-exchange behavior, luminescence, microporosity, and stability, to the material. (Triptycenedicarboxylato)zinc metal–organic frameworks (MOFs) based on paddle wheel secondary building units (SBUs) with different axial ligands have been prepared. The reproducible formation of the layered paddle-wheel structures from triptycenedicarboxylic acid (H2TDC) and zinc nitrate under various conditions seems to be characteristic of this acid and is utilized for the construction of 3D frameworks by a pillaring approach. We attempted to bring additional functionalities into MOFs by employing the appropriate pillaring ligands, for example, bis(4-pyridyl)-s-tetrazine and bis(4-pyridyl)-dimethoxy-p-phenylenedivinylene, and investigated certain properties of some MOF materials, such as guest-exchange behavior, luminescence, microporosity, and stability.