Supramolecular assemblies of Al3+ complexes with vitamin D3 (cholecalciferol) and phenothiazine. Encapsulation and complexation studies in β-cyclodextrin

Ternary assemblies of beta-cyclodextrin with cholecalciferol (or vitamin D-3) or phenothiazine and Al3+ ions were studied. The stability constants of aluminium binary complexes with cholecalciferol or phenothiazine and of ternary assemblies (beta-cyclodextrin, cholecalciferol or phenothiazine and Al3+) were determined using potentiometric titrations at 25 A degrees C (I = 0.100 M). The C-13 NMR spectra of the supramolecular structures in the solid state showed that ternary supramolecular structures associating beta-cyclodextrin, cholecalciferol or phenothiazine and aluminium(III) ions were obtained. Finally, X-ray powder diffraction patterns showed that the ternary assemblies with phenothiazine are channel type inclusion complexes.