Synthesis of meso-azulenylporphyrins.

[reaction: see text] meso-Azulenylporphyrins 1-4 were prepared by Suzuki-Miyaura coupling or the Ziegler-Hafner method. 1-Azulenyl and 6-azulenyl groups are indeed acting as electron-donating and electron-accepting substituents toward Zn(II) porphyrin. Fluorescence of Zn(II) porphyrin in the dyads is strongly quenched depending upon substitution position of azulene in order of 2 > 1 > 4 > 3.