Polarographic and spectrophotometric study of lead complexes with diethanoldithiocarbamate

Experimental and theoretical aspects concerning the behaviour of lead-dieta noldithiocarbamate complexes in aqueous solutions were studied. The reactio n occurs through complexation and formation of a yellow precipitate, which is soluble in ligand excess and in some polar solvents. The results from el ementary and gravimetric analyses show a stoichiometric relationship of 1:2 (Pb(II), DEDC). Some ambiguous interpretations have been clarified on the application in this system of Lingane's equation. Polarographic measurement s were used to determine the coordination number (congruent to 3.0) and ove rall formation constant beta MLn (congruent to 4 x 10(16)), of the lead com plexes with ammonium diethanoldithiocarbamate, which show a good agreement with previous potentiometric results for the same system. A kinetic-spectro photometric study was carried out in order to establish the decomposition o f these complexes in acid medium.