No abstract

Coordination of metal ions from aqueous solutions with metal complexes of a hexameric network tetrapyrazinoporphyrazine was studied. These compounds are complexing sorbents; their equilibrium coordination capacity largely depends on the metal occupying the coordination cavity of the porphyrazine fragments and on the external factors: kind of salt being coordinated, solution acidity, etc.Metal complexes of hexameric network tetrapyrazinoporphyrazine I contain various rigid cavities capable of coordination with metal ions: aza-24-crown-8 ([large] cavities, size~8 A), 1,9-dicarboxyN 3 -podand-3, and 1,15-dicarboxyN 5 -podand-5 [1]. The coordination activity of these fragments is provided by exocyclic porphyrazine and pyrazine nitrogen atoms containing lone s-electron pairs. This fact provides prerequisites for development of polymeric complexing sorbents with the preset coordination capacity and selectivity, based on these compounds.In a broader sense, variation of the degree of hetero substitution in the [primary surrounding] of the porphyrazine ring and its additional benz-and heterobenzannelation would provide formation of intramolecular cavities of various coordination capacities and of controllable size and geometry. This would allow development of complexing sorbents finely [tunable] to the required species (anions, cations, or neutral molecules).On the other hand, when catalytically active metal porphyrazine fragments are combined in a common conjugated system, with additional coordination of metal ions with internal cavities of the non-porphyrazine (aza crown) nature and with terminal podand fragments, a synergistic effect can be expected (especially when macrocyclic complexes of different metals are combined within the same macromolecule). Thus, the systems under consideration also show promise for the development of catalysts of a preset activity. ÄÄÄÄÄÄÄÄÄÄÄÄ 1 For communicarion I, see [1].The closest analogs of compounds I are polyphthalocyanines (H 2 Pc) i . Berezin and Shormanova studied their main physicochemical properties [2,3]; in particular, they demonstrated the feasibility of purposeful synthesis of mono-and bimetallic complexes of (H 2 Pc) i by treatment of these compounds in the solid phase with aqueous solutions of metal salts [4,5]; the optimal conditions for the metallization of (H 2 Pc) i with metal salts were found [6].In this study, we examined the complexing sorption properties of metal complexes Ia3Ic of hexameric network tetrapyrazinoporphyrazine toward Cu 2+ , Co 2+ , and Fe 2+ .We found that, when the complexes (PzcM) 6 were kept in dilute (~1 g l !1 ) aqueous solutions of bivalent metal salts CuCl 2 , FeBr 2 , and Co(COOCH 3 ) 2 , the concentration of the corresponding cation gradually decreased to a certain constant value, with the formation of bimetallic, secondary complexes (PzcM) 6 . (M`A 2 ) m , where A is an anion. The counterions arranged perpendicular to the macroring plane are the anions present in the solution.We failed to determine whether the metal ions are initially ...