BINDING, ELECTROCHEMICAL AND METAL EXTRACTION PROPERTIES OF THE NEW REDOX-ACTIVE POLYAZACYCLOALKANE CENYLMETHYL)-1,4,7,10,13,16-HEXAAZACYCLOOCTADECANE

The redox-functionalised polyazacycloalkane receptor cenylmethyl)-1,4, 7,10,13,16-hexaazacyclooctadecane (L-1) has been designed and synthesi zed and its binding, electrochemical and metal extraction properties s tudied. The results have been compared to those obtained for the paren t redox-active polyazacycloalkane rrocenylmethyl)-1,4,8,11-tetraazacyc lotetradecane, L-3. The cadmium complex of L-1 and the free receptor L -3 have been crystallographically characterised. The structure of [CdL 1][PF6](2). 4CH(3)CN . 4H(2)O consists of cationic [CdL1](2+) units in which the cadmium ion exhibits a distorted octahedral environment. So lution studies by potentiometric methods have also been carried out in the presence of H+ and Cu2+ in 1,4-dioxane-water (70:30 v/v, 25 degre es C, 0.1 mol dm(-3) KNO3) for L-1 and thf-water (70:30 v/v, 25 degree s C, 0.1 mol dm(-3) [NBu4n][ClO4]) for L-3. Electrochemical experiment s as a function of the pH in the presence of Ni2+, Cu2+, Zn2+, Cd2+ or Pb2+ have been carried out for L-1 and L-3. The solvent extraction pr operties of L-1 have also been studied.