Cobalt, zinc, hydroxoaluminum, and iron complexes of N,N`,N``,N```-tetrakis(b-diethylaminoethyl)phthalocyanine-2,3 : 9,10 : 16,17 : 23,24-tetrakis(dicarboxamide) were synthesized and were converted into the corresponding water-soluble quaternary salts by treatment with methyl iodide, methyl p-toluenesulfonate, diethyl and dimethyl sulfates, and trimethyl phosphate. The electronic absorption spectra of the quaternary salts indicated their considerable aggregation in aqueous solution; the degree of aggregation decreases in going to solutions in ethanol and disappears in DMSO.The present work continues the series of our studies on the synthesis of symmetric phthalocyanine derivatives based on octa-4,5-carboxyphthalocyanine metal complexes (Pc) containing functional groups which make these compounds soluble in water and aqueous media. We previously [2, 3] synthesized a series of covalent conjugates from anionic octa-4,5-carboxyphthalocyanine metal complexes and a-amino acids, namely the corresponding tetra-N-carboxymethylimides and octa-4,5-N-methyl-N-carboxymethylcarboxamides. The products were soluble in organic solvents and water, and their molecules retained the D 4h symmetry typical of unsubstituted phthalocyanine. However, we found that these compounds strongly tend to aggregate in aqueous media [2,3]. With a view to eliminate aggregation, we synthesized a new series of water-soluble conjugates from anionic carboxyphthalocyanine complexes and sulfo analogs of a-amino acids, namely taurine-substituted octa-4,5-carboxyphthalocyanine complexes [4,5]. The resulting tetra-N-(2-sulfoethyl)imides (as free acids or sodium salts) were fairly readily soluble in water, ethanol, and dilute hydrochloric acid. Their electronic absorption spectra recorded from solutions in aqueous sodium hydroxide displayed a distinct vibrational structure, indicating that the degree of aggregation in solution is small. We also tried to obtain cationic water-soluble phthalocyanine complexes containing quaternary ammonium salt fragments [1,4]. Such ÄÄÄÄÄÄÄÄÄÄÄÄ 1 For communication XXXIX, see [1].compounds attract interest as effective sensitizers for photochemical inactivation of microbial pathogens [6] and catalysts for oxidation of organic substrates [7]. For example, metal complexes derived from octakis-(2-chloroethyl) phthalocyanineocta-4,5-carboxylates react with trimethylamine to afford the corresponding octakis-4,5-(b-trimethylammonioethoxycarbonyl)-substituted octachlorides which may be regarded as complete choline esters of octa-4,5-carboxyphthalocyanines. The resulting quaternary salts were extremely hygroscopic, very readily soluble in water and dilute hydrochloric acid, and soluble in alcohols and aprotic polar solvents like DMSO or DMF. Unlike DMSO, the electronic absorption spectra of these salts in aqueous solution revealed a considerable aggregation [5].In the present work we synthesized previously unknown N,N`,N``,N```-tetrakis(b-diethylaminoethyl)-phthalocyanine-2,3 : 9,10 : 16,17 : 23,24-tetrakis(dicarboxamide) complexes ...