An exotic band structure of a supramolecular honeycomb lattice formed by a pancake π-π interaction between triradical trianions of triptycene tribenzoquinone.

A supramolecular honeycomb lattice was successfully formed by using triradical trianion species of triptycene tribenzoquinone (TT) which forms strong intermolecular π-π pancake bonds toward three directions. The crystal structure of Rb3TT·2H2O belongs to the hexagonal P6/m space group, the tight-binding band calculation of which reveals Dirac cones and flat bands.