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

Reaction of cerium(III) acetylacetonate with lithiated tetrakis(4-pyri dyl)porphyrin, tetrakis(4-(dimethylamino)-phenyl) porphyrin, and tetra kis (4-(methoxycarbonyl)phenyl)porphyrin in trichlorobenzene at 200-de grees-C yields the corresponding neutral cerium(IV) bisporphyrinates C e(TPyP)2, Ce(TMAP)2, and Ce(TMeCPP)2, respectively. Quaternarization o f 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+, respectiv ely. Ce(III) in the two heptacations is oxidized to Ce(IV) with bromin e to obtain the corresponding octacations. The cations are isolated as halides or hexafluorophosphates. Saponification of the ester groups i n Ce(TMeCPP)2 with KOH gives the octacarboxylate [Ce(IV)(TCPP)2]8-, wh ich is hydrolyzed to a dianion and precipitated as a bis(triphenylphos phoranediyl) ammonium salt, (PPN)2[Ce(TH3CPP)2]. The ionic Ce(III) and Ce(IV) porphyrin double deckers including [Ce(IV)(TH4PyP)2]8+, the oc taprotonated form of Ce(TPyP)2, are identified by UV/Vis and H-1 NMR s pectra and gel electrophoresis at polyacrylamide or agarose gels in aq ueous buffer solutions at pH 8.