Synthesis of tetra(tricarbethoxy)- and tetra(dicarboxy)- substituted soluble phthalocyanines

Abstract

Pd (II), Co (II), Cu (II) and Zn (II) phthalocyanines with a tricarbethoxyethyl substituent on each benzo group were prepared from 4-(1,1,2-tricarbethoxyethyl)-phthalonitrile and the corresponding divalent metal salt at 170°C. Transesterification occurred when the reaction was carried out in pentanol. Treatment of the palladium complex with sodium ethoxide at room temperature and further acidification resulted with tetra(1,2-dicarboxyethyl)phthalocyaninatopal-ladium. Its UV-vis spectrum in aqueous solution indicated dimeric and monomeric species at pH ≈ 12, but at pH ≈ 6 only the dimeric form were present.