Synthesis and spectral properties of novel metal-free and metallophthalocyanines bearing four 19-membered tetrathiadiaza macrocycles

The synthesis of novel metal-free phthalocyanine 3 and metallophthalocyanines 4, 5 and 6 containing four 19-membered tetrathiadiaza macrocycles at the peripheral positions are described for the first time. All new compounds were characterized by a combination of elemental analysis and 1H NMR, 13C NMR, IR, UV–Vis and MS spectral data. The metallophthalocyanines 4, 5 and 6 have good solubility in organic solvents DMSO, DMF and THF. The aggregation behaviors of metal-free phthalocyanine 3 and metallophthalocyanines 4, 5 and 6 were investigated at different concentrations in DMF and THF. All metallophthalocyanines were found to exist in monomeric form in DMF and THF at concentrations between 10 × 10−6 and 2 × 10−6 mol dm−3. As the concentration increased to 5 × 10−5 mol dm−3, a deviation from ideality was observed due to the presence of aggregated species for all phthalocyanines.