Chelating properties of permethylated 6(A),6(D)-dideoxy-6(A),6(D)-bis(1-imidazolyl)cyclodextrins towards Pt(II) and Ru(III)
Résumé
Two imidazole-coordinating groups have been successfully grafted onto the C-6A and C-6D positions of permethylated α- and β-cyclodextrin scaffolds. Both water-soluble ligands L1 and L2 turned out to behave as good chelators when reacted with K2PtCl4. In the resulting diamagnetic cis-chelate complexes, the metal cation is pending above the cavity entrance. Paramagnetic ruthenium(III) chelate complexes have also been successfully synthesised from L1 and L2. In these more sterically demanding octahedral complexes, the imidazole groups coordinate the metal centre in a trans-fashion.