Band structures of porous graphenes

Band structures of porous graphenes are deduced by crystal orbital method. The dispersions suggest ca. 3.7 eV of band gaps. Bandwidths of the HOCOs and LUCOs are zero within Hückel approximation due to the nodal character of phenylene units. The graphene ribbons with n porous ladders also have singular electronic states, of which flat HOCOs and LUCOs are n-fold degenerate, respectively. The flat bands are useful for possible magnetic materials.