Tetra-2,3-Pyrazinoporphyrazines with Externally Appended Pyridine Rings 22 Synthesis, Physicochemical and Photoactivity Studies on In(III) Mono- and Heteropentanuclear Complexes

The basic macrocyclic octapyridinotetrapyrazinoporphyrazine InIII complex of formula [Py8TPyzPzIn(OAc)]·8H2O, prepared by reaction of the free ligand [Py8TPyzPzH2]·2H2O with In(OAc)3, is a stable-to-air species of which the structure has been studied by its X-ray powder diffraction and mass spectra and characterization operated by IR and UV-visible spectral behavior. The complex has been further examined and proven to be of potential interest for its response as an anticancer agent in the field of photodynamic therapy (PDT), the value of ΦΔ = 0.55 (in DMF) being in the range of 0.4–0.6 at the level of similar phthalocyanine and porphyrazine analogs and qualifying the species as a highly efficient anticancer agent. Planned parallel types of investigation, including their photoactive behaviour in PDT, have been extended to the mononuclear octacation [(2-Mepy)8TPyzPzIn(OAc)]8+ (salted by iodide ions) and the heteropentanuclear derivatives [(M’Cl2)4Py8TPyzPzIn(OAc)]·xH2O (M’ = PdII, x = 8; PtII, x = 1)) and [{(Pd(CBT)2)4}Py8TPyzPzIn(OAc)]·19H2O (CBT = m-carborane-1-thiolate anion).