Ladder Acenes: Staircase-Bending Nanographenes.

Two nonplanar nanographenes, namely, L8 and L9, were developed by linearly fusing two contorted hexabenzocoronene subunits into an octacene and a nonacene backbone, respectively. Single-crystal X-ray diffraction revealed their staircase-bending backbones and waggling periphery benzenoid rings with lengths of 1.95 and 2.18 nm, respectively. Such ladder acene architectures reduce the structural symmetry and modulate the electronic structures. This work presents the first molecular model system of staircase-bending nanographenes with promising optoelectronic properties.