Antioxidant activities of the new tetrasubstituted metal-free, Zn(II) and Co(II) monophthalocyanines

4-[(4'-(Tert-butyl) phenoxy) phenoxy] phthalonitrile 1 has been prepared by the reaction of 4-(4-nitrophenoxy) phthalonitrile with 4-tertiarylbutylphenole. 4-((4'-tert-butyl) phenoxy) phenoxy tetrasubstituted metal-free 2, zinc(II) 3 and cobalt(II) 4 phthalocyanines have been prepared by tetramerization of compound 1. The synthesized phthalocyanines showed high solubility in common organic solvents such as CHCl3. All compounds were characterized by elemental analysis and H-1-NMR, C-13-NMR, UV-vis, IR spectra. Aggregation behaviors of these compounds have been investigated in different solvents (CHCl3, THF, DMF and DMSO) and different concentrations in CHCl3. The in vitro antioxidant activities of phthalocyanine compounds 2, 3 and 4 were evaluated in a series of assays involving DPPH radicals, hydroxyl radicals, superoxide radicals, singlet oxygen and hydrogen peroxide. Antioxidant activity of compound 2 was found to be higher than that of compounds 3 and 4.