Synthesis of a new trans-A2B2 phthalocyanine motif as a building block for rodlike phthalocyanine polymers.

Polyphthalocyanines have potential application in the development of electronic materials. One-dimensional polyphthalocyanines are accessible through monomers having a trans-A2B2 structure, but the preparation of a truly linear polyphthalocyanine is challenging because of limitations imposed by the geometry of phthalocyanines and the methodology for their synthesis. Benzimidazoporphyrazines are a known class of extra-annulated phthalocyanines. A trans-A2B2 benzimidazoporphyrazine is geometrically suitable for the preparation of rodlike polymers. A new synthesis of benzimidazoporphyrazines is presented as a stepping stone to the synthesis of trans-A2B2 benzimidazoporphyrazines.