Synthesis and characterization of a β-fused tetraporphyrin-phthalocyanine star-shaped array

A star-shaped array, consisting in four tetraphenylporphyrin fused to a phthalocyanine central unit by pyrazine groups, is constructed via the condensation reaction of a dicyanoquinoxaline annulated to a porphyrin ring. The nature of the annulated group is critical for the success of the reaction; in the case of smaller linkers, such as a dicyanopyrazine unit, a nucleophilic substitution occurred, giving the corresponding alcoxy derivative in alcoholic solvents. The visible spectrum of the array shows the typical absorptions of the macrocyclic sub units. The synthetic pathway here presented opens the way to the preparation of β-fused porphyrin-phthalocyanine arrays.