Conformational features and coordination properties of functionalized β-cyclodextrins. Formation, stability and structure of proton and copper(II) complexes of 3A-[1-(2-amino)ethylamino]-3A-deoxy-2A(S),3A(R)-β-cyclodextrin

The functionalized cyclodextrin 3A-[1-(2-amino)ethylamino]-3A-deoxy-2A(S),3A(R)-β-cyclodextrin was synthesized and an NMR, EPR, pH-metric and calorimetric investigation was carried out in aqueous solution in order to ascertain its behavior towards proton and copper(II) complexation. The NMR spectra show the involvement of functionalizing moiety in H-bond formation, in keeping with the ΔH° and ΔS° values. The potentiometry and EPR results display the involvement of secondary OHs, particularly of 2-OH in the complexation of copper(II).