Supramolecular assembly of sandwich-type heteroleptic lanthanum (Porphyrinato)(Phthalocyaninates)

Concentration and cation-induced supramolecular assembly of heteroleptic double- and triple-decker [An4P]La[(15C5)4Pc] and [An4P]La[(15C5)4Pc]La[An4P] lanthanum complexes (An4P2− = 5,10,15,20-tetra-(4-methoxyphenyl)-porphyrinate dianion and(15C5)4Pc2− = tetra-(15-crown-5)-phthalocyaninate dianion) is studied. Double-decker [An4P]La[(15C5)4Pc] complex is shown to be susceptible to effective concentration-driven assembly determined by the deviation from the Beer-Lambert-Bouguer law up to a concentration of 10−6 M. Triple-decker [An4P]La[(15C5)4Pc]La[An4P] complex is not inclined to the concentration-driven assembly up to a concentration of 10−4 M. The interaction between the receptors and sodium or potassium salt is determined by the receptor structure and independent of the salt anion. When interacting with potassium salts, the double-decker complex can form a supramolecular cofacial dimer. In the case of the triple-decker complex, the crown-phthalocyanine deck of the molecule is sterically blocked, and supramolecular aggregates do not form. Sodium cations can be encapsulated in the crown ether rings of both receptors.