Tetrapyrazinoporphyrazines and their metal derivatives. Part II: Electronic structure, electrochemical, spectral, photophysical and other application related properties

Tetrapyrazinoporphyrazines (TPyzPzs), the heterocyclic azaanalogs of the phthalocyanine macrocycle, known since the 1930 s, but became an object of intensive studies in the last decades. In Part I (Coord. Chem. Rev. 2016, 309, 107–179) the synthesis of variously substituted TPyzPzs and their metal complexes as well as of their precursors was presented. In the present Part II, we consider the peculiarities of their electronic structure, electrochemical, spectral, acid–base and photophysical properties. The focus is made on the related perspectives of practical applications in the fields of nonlinear optical properties, liquid crystals, catalysis, sensors, dark quenchers of fluorescence, photodynamic therapy (PDT, including the specific aspects of water-soluble and targeting TPyzPzs, in vitro PDT results, bi- and multimodal therapy) and light harvesting.