Voltammetric analysis of Cs+-DB18C6 complexes stoichiometry at the water/1,2 - dichloroethane interface

S.A. DASSIE; L.M. YUDI; A.M. BARUZZI

ELSEVIER SCIENCE SA

Lugar: Amsterdam; Año: 1999 vol. 464 p. 54 - 54

he transfer of Cs across the water 1,2-dichloroethane interface assisted by dibenzo-18-crown-6 (DB18C6) was studied using cyclic voltammetry in a concentration range wide enough to fulfil the following experimental conditions: cCs(w)cDB18C6(o), cCs(w)cDB18C6(o) and cCs(w)cDB18C6(o). In all cases, the total voltammetric current comprises two transfer processes which were compared with the theoretical voltammograms for facilitated transfer by using different models. From the results obtained, a first electrochemical step of Cs transfer with interfacial formation of the complex (Cs: DB18C6) 1:2 was followed by a second electrochemical step with formation of the complex 1:1. The relative contribution of each process to the global current depends on the concentration ratio (lcCs:cDB18C6) employed. At high l values, the 1:1 complex is formed through the interfacial destruction of the 1: 2 complex, and at low l values, through the facilitated transfer of M(w) by L(o). An important as