New water soluble cationic zinc phthalocyanines as potential for photodynamic therapy of cancer

The novel phthalonitrile derivatives (2 and 3) bearing 2-[3-(dimethylamino)phenoxy]ethanol substituents on the 3 and 4 positions have been synthesized. The novel peripherally and non-peripherally tetra-{2-[3-(dimethylamino)phenoxy]} substituted zinc phthalocyanines (2a and 3a) were also synthesized by cyclotetramerization of phthalonitrile derivatives (2 and 3). The obtained new zinc phthalocyanines (2a and 3a) were converted into water-soluble quaternized products (2b and 3b). The new compounds have been characterized by combination of spectroscopic data including UV–Vis, IR, 1H NMR, 13C NMR, MS spectroscopic data and elemental analysis as well. The photophysical and photochemical properties of newly synthesized zinc phthalocyanines were investigated in DMSO for non-ionic and in both DMSO and phosphate buffer solution (PBS) for ionic compounds. The obtained ionic complexes (2b, 3b) show excellent solubility in both organic and aqueous solutions which is very useful for the treatment of cancer by photodynamic therapy (PDT).