Ion channel containing mesophases : structural characteristics of condensed phases of crown-ether-substituted phthalocyanines
Résumé
A copper complex of a phthalocyanine substituted with four benzo-15-crown-5 1,Cu and the corresponding dihydrogeno-derivative 1,H2 were synthesized. X-ray determinations at small angles permitted us to characterize two types of condensed phases. Solid phases with orthorhombic structure were found for 1,H2 and for 1,Cu (a=20.5, b= 18, c=4.2 Å). In these forms, two-dimensional rectangular arrays of substituted phthalocyanines lead to corrugated planes. Phthalocyanine moieties are superposed in an eclipsed conformation and the crown-ether macrocycles form channels. Metastable mesophases could also be characterized by X-ray diffraction. In this case, only two broad lines at 20.8 and 8.2 Å and two halos at 3.5 and 4.2 Å are observed for 1,Cu. The dihydrogeno-derivative leads to a similar pattern but only one halo is noticed at 4.2 Å. The mesophases are constituted of two-dimensional square lattices superposed in a staggered conformation.