Fig. 1: Design principle of phthalocyanine-based 2DCPs.

a, Schematic showing the phthalocyanine-based 2DCPs connected by different conjugated linkages (in the pale ellipses) and the selected model compounds MX (X = 1−6). C, grey; N, lavender; H, white. b, HOMO−LUMO energy levels and gaps of M1−M6. c, Molecular electronic structures of the frontier orbitals of M6.