THE ENHANCED TRANSPORT OF THE CADMIUM ACETYLACETONE COMPLEX ACROSS THE ADSORBED ALIPHATIC ALCOHOL MONOLAYER DURING ELECTROREDUCTION ON MERCURY-ELECTRODES

The electrode reaction of the Cd2+ complex with acetylacetone (Acac) w as studied on mercury electrodes in the absence and in the presence of n-pentanol and n-octanol. In the inhibitor free solution and under co nditions where Cd(Acac), complex predominated, the standard rate const ant of the cadmium reaction was found to be 6.2 x 10(-2) cm s(-1). In the presence of inhibitors, it was determined from cathodic and anodic reaction orders with respect to Acac, that the Cd(I)(Acac) species re acted directly with the electrode. In the presence of n-pentanol and n -octanol adsorbed on electrodes, the electrode reaction of the Cd-aq(2 +) \ Cd(Hg) system with hydrated Cd2+ ions proceeds more than one orde r of magnitude slower than the reaction of Cd-acetylacetone complexes. The ionophoretic effect of Acac is postulated to he due to the intera ction of the reactant with the adsorbed surface layer. (C) 1998 Elsevi er Science S.A. All rights reserved.