Key points are not available for this paper at this time.
Extending conjugation: Azulene-fused porphyrins (see example) are synthesized through the oxidation of meso-(4-azulenyl)porphyrins with FeCl3. The azulene-fused strategy allowed highly π-conjugated porphyrinic electronic systems, which are promising two-photon absorption pigments, to be realized.
Kurotobi et al. (2006) studied this question.