METAL-COMPLEXES WITH TETRAPYRROLE LIGANDS .71. HETEROAGGREGATION OF CATIONIC METAL MONOPORPHYRINATE AND BISPORPHYRINATE WITH ANIONIC METAL PORPHYRINATES OR INDIGOSULFONATES

The formation of binary or ternary porphyrin heteroaggregates of the t ype AB, BC, BC2 or ABC is investigated by UV-Vis spectrophotometry (1: 1 mixtures and Job's method of continuous variation), precipitation an d electrophoresis. Components are: A = anionic acceptor molecule, e.g. indigotetrasulfonate, (inds(4))(4-); B = cationic metal monoporphyrin ate, e.g. the tetrakis(trimethylammoniophenyl)porphyrin derivative [Cu (ttm(4)ap)](4+) (2h-Cu), or cationic metal bisporphyrinate, e.g. [Ce(t m(4)pyp)(2)](7+) (3d, the cerium(III) double-decker derived from tetra kis (4-methylpyridinio) porphyrin (1d)); C = anionic metal complexes o f tetrakis(4-sulfonatophenyl)porphyrin, [M(tpps(4))](4-) (2j-M, M=Cu, Zn, Ni, VO, Mn(H2O), OsO2, and OsL(2) with L = 1-methylimidazole). Agg regation in the binary system A/B always followed 1:1 stoichiometry fo r indigooligosulfonates (inds(n))(n-) (n = 2, 3, 4) and [Cu(ttm(n)ap)] (n+) (n = 3, 4; 2g/2h-Cu) or (inds(4))(4-) and [Ce(tm(4)pyp)(2)](7+) ( 3d). In the system B/C, pure samples of Zg-Cu or 2h-Cu and [Zn(tpps(n) )](n-) (n = 3, 4; Zi-Zn, 2j-Zn) all formed 1:1 aggregates BC with each other. Impure samples produced spectral artifacts. [Ce(tm(4)pyp)(2)]( 7+) (3d) and [Ce(tH(4)pyp)(2)](8+) (3b-H-8, prepared by N-protonation of Ce(tpyp)(2) (3b), the double-decker derived from tetrakis(4-pyridyl )porphyrin) (1b)) formed aggregates in ratios 1:1 with (inds(4))(4-) a nd 1:2 with [M(tpps(4))](4-) (2j-M; M = Ni, VO, Mn(OH2)) which were re cognised by Job diagrams or precipitation and analysis, respectively [ Ce(ttm(4)ap)(2)](8+) (3h) and [M(tpps(4))](4-) (2j-M) form 2:1 aggrega tes in solutions from which after weeks peculiar solids precipitate th at are redissolved on shaking. The slow formation of these aggregates is also shown by electrophoresis, while solids containing [Ce(tm(4)pyp )(2)](7+) (3d) are rapidly deposited. The spectrophotometric analysis of a ternary system A/B/C, e.g. s(4)](4-)/[Ce(tm(4)pyp)(2)](7+)/[Ni(tp ps(4))](4-), disclosed an interaction of all species, but no definite stoichiometry. Homoaggregation of [Ni(tpps(4))](4-) (2j-Ni) and [inds( 4)](4-) was not observed.