Effect of second-sphere coordination 9. Partial inclusion of pentaammineruthenium(II) and pentacyanoferrate(II) complexes with nitrogen heterocycles into a cyclodextrin cavity

The inclusion of pentaammineruthenium(II) and pentacyanoferrate(II) complexes with nitrogen heterocycles into cyclodextrins was investigated by UV-visible spectrophotometry, H-1-NMR spectroscopy, and cyclic voltammetry. The stability constants of the inclusion adducts of the metal complexes into cyclodextrins were determined by capillary electrophoresis. The complexes form adducts with cyclodextrins by the inclusion of an aromatic ligand moiety of the complex into the cavity of cyclodextrins. The adduct formation caused a modification of the redox behavior of the complex. The stability of the cyclodextrin adduct was influenced by the included aromatic ligand of the complex and the cavity size of cyclodextrin, especially the positive charge on the aromatic ligand.