Selectively Extending the Curved Side of N-Doped Hexa-peri- hexabenzocoronene.

A curved nanographene, conceptually by insertion of nitrogen into a trapezoidal planar nanographene at the edge was synthesized by π-extension of the nitrogen-doped hexa-peri-hexabenzocoronene. This N-doped nanographene exhibited a π-electronic concave face containing a nonaromatic azepine ring in the middle with a size of 14.0 Å length and 4.0 Å depth, which represents an unprecedented half-side concave geometry of curved nanographene. The bent π-extension exhibited a low degree of conjugation suggested by calculation results. Due to the unique 3D structure and electron-rich property, this nanographene showed pronounced intermolecular charge transfer with C.