Highly Electron‐Donating Antiaromatic <i>N</i>,<i>N′</i>‐Dimethyldiazaporphyrins via Reductive Dimethylation

Ni(II) N , N ′‐dimethyl‐5,15‐diazaporhyrins are efficiently prepared through reductive dimethylation of 5,15‐diazaporphyrin Ni(II) complexes with sodium dispersion in the presence of dimethyl sulfate. The obtained reduced diazaporphyrins exhibit highly upfield‐shifted 1 H NMR spectra and narrowed HOMO–LUMO gaps originating from their distinct antiaromatic nature. The electrochemical analysis reveals their highly electron‐donating property, which leads to the formation of a charge transfer (CT) complex with tetracyanoquinodimethane (TCNQ) as an electron acceptor. The CT complex of Ni(II) N , N ′‐dimethyl‐10,20‐diphenyl‐5,15‐diazaporphyrin with TCNQ exhibits alternate π‐stacking orientation in the solid state. N , N ′‐Dimethyl‐5,15‐diazaporphyrins also interact with C 60 in the solid state to yield cocrystals.