Tetra-2,3-pyrazinoporphyrazines with Peripherally Appended Pyridine Rings. 20. Mono- and Pentanuclear Al and Ga Complexes: Synthesis and Physicochemical and Photoactivity Studies.

The autocyclotetramerization of the precursor 2,3-dicyano-5,6-di(2'-pyridyl)pyrazine [(CN)PyPyz] in the presence of MCl compounds (M = Al, Ga) leads to the formation of the new mononuclear porphyrazine complexes [PyTPyzPzMCl]·HO (PyTPyzPz = tetrakis-2,3-[5,6-di(2-pyridyl)pyrazino]porphyrazinato anion). From these species, the hydroxide analogues [PyTPyzPzMOH]·HO were obtained by contact with hot water, and their corresponding pentanuclear species [(PdCl)PyTPyzPzMCl]·HO could be easily formed by the reaction with PdCl. Physicochemical characterization of the mono- and pentanuclear macrocycles was based on elemental analysis, and mass, powder X-ray, and IR spectra.