METAL-COMPLEXES WITH TETRAPYRROLE LIGANDS .68. SYNTHESIS OF WATER-SOLUBLE OSMIUM PORPHYRIN COMPLEXES

The synthesis of osmium tetraphenylporphyrinates with functional groups in the para-position of the phenyl rings is described. By sulfonation of the corresponding para-unsubstituted complex the carbonylosmium(II)-complex [OsCO(TPPS4)H2O]4- or the dioxoosmium(VI)-complex [OsO2(TPPS4)]4- [(TPPS4)6-: hexa-anion of tetrakis(4-sulfonatophenyl)porphyrin] is obtained. The osmochrome complex [Os(TPPS4)(1-Meim)2]4- , which changes to the osmichrome complex [Os(TPPS4)(1-Meim)2]3- in the presence of air, is formed from the dioxo-compound by reduction. These anions are deposited as water-soluble sodium- or as water-insoluble tetraphenylarsonium salts. The novel osmochrome complex Os(TMeCPP)(1-Meim)2 [TMeCPP)2-: dianion of tetrakis(4-methoxycarbonylphenyl)porphyrin] is transformed by alcaline saponification and precipitation with hydrochloric acid to the corresponding alcali-soluble osmochrome tetracarbonic acid Os(TH4CPP)(1-Meim)2. UV/VIS-, H-1-NMR-spectra and electrophoreses provide insight into the behaviour of the osmium-porphyrinate anions in water.