Synthesis and properties of styryl-substituted tetrapyrazinoporphyrazines [St8PyzPzM], M = 2NaI, MgII(H2O) and ZnII

New styryl-substituted tetrapyrazinoporphyrazines [St8PyzPzM] (M = 2NaI, MgII(H2O) and ZnII; St = -CH=CHAr, where Ar = phenyl or cumyl) were prepared by template cyclotetramerization of 5,6-distyrylpyrazine-2,3-dicarbonitriles available from condensation of diaminomaleodinitrile with the substituted cinnamils (StCO) 2 obtained from biacetyl and arylaldehydes ArCHO. The new porphyrazine macrocycles were characterized by electronic absorption and emission spectra, which provide evidence of efficient π-interaction of the peripheral styryl moieties with the central pyrazinoporphyrazine framework. The electronic excitation of the stylbenoid chromophore in the near UV-region (400 nm) leads to strong emission of the porphyrazine chromophore near 700 nm, allowing to consider the styryl-substituted porphyrazines as efficient light-harvesting species. Their spectral properties and electrochemical behavior are compared with those of stylbenoid phthalocyanines and peripherally substituted tetrapyrazinoporphyrazines. © 2010 World Scientific Publishing Company.