Synthesis of Nanographene-Fused Carbaporphyrin(2.1.0.1) and Its Organopalladium(II) Complex

New nanographene ligands are indispensable for expanding the metal-doping chemistry of nanographenes. In this study, by incorporating an <i>o</i>-dipyrrolylbenzene unit into the bay region of an iconic nanographene, hexa-<i>peri</i>-hexabenzocoronene (HBC), we synthesized nanographene-fused carbaporphyrin(2.1.0.1) (<b>1</b>). Compound <b>1</b> displayed a nonaromatic character, as indicated by ¹H NMR spectroscopy, single-crystal X-ray structure analyses, and nucleus-independent chemical shift (NICS) calculations. Additionally, <b>1</b> featured a dianionic cavity with an <i>adj</i>-CCNN core capable of stabilizing the Pd^II cation. Both the ligand and its organopalladium(II) complex adopted a distorted chair conformation. Compared to free ligand <b>1</b>, complex <b>1</b>·Pd showed red-shifted UV-vis absorption, aligning with the reduced electrochemical and calculated HOMO-LUMO gaps. The marked differences between <b>1</b> and previously reported HBC-fused carbaporphyrin(1.1.1.0) indicate that slight modifications to the pyrrolic unit significantly altered the electronic structure and metal-doping behavior of the nanographene ligand.