The syntheses, characterization and properties of some metallophthalocyanine complexes substituted by (N-(2-hydroxyethyl)piperazine)-N′-2-ethane sulfonic acid (HEPES)

Eight novel piperazine derivatives of metal (Zn, Co, Ni, Cu) phthalocyanine complexes were synthesized from two precursors obtained by the nucleophilic substitution of (N-(2-hydroxyethyl)piperazine)-N′-2-ethane sulfonic acid (HEPES) with both 3-nitro-phthalonitrile and 4-nitro-phthalonitrile. The complexes are characterized by IR, elemental analysis, 1H NMR and mass spectroscopy; the UV–vis absorption spectra, rate of singlet oxygen yields, fluorescence spectra and quantum yields of the compounds are discussed.