METAL-COMPLEXES WITH TETRAPYRROLE LIGANDS .67. SYNTHESIS AND SPECTROSCOPIC PROPERTIES OF WATER-SOLUBLE CERIUM BISPORPHYRINATE DOUBLE-DECKER IONS

Reaction of cerium(III) acetylacetonate with lithiated tetrakis(4-pyridyl)porphyrin, tetrakis(4-(dimethylamino)-phenyl) porphyrin, and tetrakis (4-(methoxycarbonyl)phenyl)porphyrin in trichlorobenzene at 200-degrees-C yields the corresponding neutral cerium(IV) bisporphyrinates Ce(TPyP)2, Ce(TMAP)2, and Ce(TMeCPP)2, respectively. Quaternarization of the former two double deckers with methyl tosylate, 2-chloroethanol, or methyl iodide produces salts of the octaalkylated cations [Ce(III)(TM4PyP)2]7+, [Ce(III)(TE4PyP)2]7+, and [Ce(IV)(TTM4AP)2]8+, respectively. Ce(III) in the two heptacations is oxidized to Ce(IV) with bromine to obtain the corresponding octacations. The cations are isolated as halides or hexafluorophosphates. Saponification of the ester groups in Ce(TMeCPP)2 with KOH gives the octacarboxylate [Ce(IV)(TCPP)2]8-, which is hydrolyzed to a dianion and precipitated as a bis(triphenylphosphoranediyl) ammonium salt, (PPN)2[Ce(TH3CPP)2]. The ionic Ce(III) and Ce(IV) porphyrin double deckers including [Ce(IV)(TH4PyP)2]8+, the octaprotonated form of Ce(TPyP)2, are identified by UV/Vis and H-1 NMR spectra and gel electrophoresis at polyacrylamide or agarose gels in aqueous buffer solutions at pH 8.