Triptycene 1,2-Quinones and Quinols: Permeable Crystalline Redox-Active Molecular Solids

Suitably designed quinones and quinols
are promising modules for
the programmed construction of ordered redox-active molecular solids.
To explore this potential, we have synthesized compounds 1–4, in which multiple 1,2-benzoquinone and 1,2-quinol
units are attached to a triptycene core. The resulting molecules have
topologies that disfavor efficient packing, and structural studies
show that they crystallize to form open networks held together by
characteristic attractive intermolecular forces, including O–H···O
hydrogen bonds, C–H···O interactions, π-stacking,
and dipolar interactions. Remarkably, the resulting solids are permeable
and can undergo reversible redox reactions without loss of crystallinity.
Our work may thereby help lead to the design of robust carbon-based
batteries with electrodes derived from quinones, quinols, and other
redox-active molecules abundantly produced by nature.