Phenylene‐Bridged Expanded Porphyrazines

Abstract Novel expanded porphyrazines comprising o ‐ and p ‐phenylene units were synthesized from self‐condensation reactions of acyclic [2+1]‐type precursors prepared from 1,3‐diiminoisoindoline and the corresponding phenylenediamines. Möbius and Hückel topological structures of [4+2]‐type and [3+2]‐type expanded porphyrazines, respectively, were elucidated by X‐ray crystallography. Despite the Möbius and Hückel [4 n ]π‐electron systems, these expanded porphyrazines are virtually nonaromatic as a result of their flexible structures in solution, which may diminish intrinsic aromaticity and antiaromaticity.