The synthesis and complexation properties of multidentate per-[6-deoxy-6-thio-(4-pyridyl)]-cyclodextrins

The synthesis of chemically modified multidentate cyclodextrins capable of carrying pyridyl ligands is reported. Per-(6-bromo-6-deoxy)-alpha-, -beta-, and -gamma-cyclodextrins (1, 2, and 3, respectively) were treated with an excess of 4-mercaplopyridine affording per-[6-deoxy-thio-6-(4-pyridyl)]-alp ha-, -beta-, and -gamma-cyclodextrin derivatives in very high yields (90-95 % for isolated products). The solubilities of such systems in non-aqueous s olvents were efficiently increased by acetylation of the secondary hydroxyl groups. The complexation properties of the derivatives with regard to copp er(II) were investigated by solvent extraction, ESR and spectroscopic titra tion experiments.