[5]helicene-fused phthalocyanine derivatives. New members of the phthalocyanine family.
An efficient synthetic route to fuse [5]helicene moieties around the phthalocyanine core is reported. The helicene moiety was constructed by the Diels-Alder reaction of 3,4,3',4'-tetrahydro-1,1'-dinaphthyl and dibromobenzyne. Subsequent cyanation, oxidation, O-alkylation, and cyclic tetramerization resulted in octaalkoxy phthalocyanine derivatives which showed high solubility in common organic solvents and displayed strong absorption in the near-IR region.