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

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 degreesC. 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-oxyethyI)phthalocyaninatopalladium. Its UV-vis spectrum in aqueous solution indicated dimeric and monomeric species at pH approximate to12, but at pH approximate to 6 only the dimeric form were present. Copyright (C) 2003 Society of Porphyrins & Phthalocyanines.