1H-NMR study of heavy metals complexation with hexakis(3,6-anhydro) tetrakis(2A,B,D,E-O-octyl) cyclomaltohexaose (OCT).

The selection of the cations bound by hexakis (3,6-anhydro) tetrakis (2A,B,D,E-O-octyl) cyclomatohexaose (OCT) was performed by thin layer chromatography. The three cations selected, UO(2)2+, Pb2+ and Hg2+ were then studied by 1H-NMR. A 2:1 OCT/cation stoichiometry was identified in the cases of UO(2)2+ and Pb2+. While UO(2)2+ binding (logK around 6) followed a fast exchange kinetics, a slow or intermediate complexation was found with Pb2+ (logK = 5.6) and Pb2+, respectively. In the latter case, the poor solubility of Hg2+ precluded to propose neither a stoichiometry nor an estimation of the affinity constant.