Polarographic and Spectrophotometric Study of Lead Complexes with Diethanoldithiocarbamate

• Autor(a) principal: Marques,A.L.B.
• Data de Publicação: 1998
• Outros Autores: Chierice,G.O.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Journal of the Brazilian Chemical Society (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50531998000600005
• topic: lead; dithiocarbamate complexes; spectrophotometry; polarography; potentiometry

Experimental and theoretical aspects concerning the behaviour of lead-dietanoldithiocarbamate complexes in aqueous solutions were studied. The reaction occurs through complexation and formation of a yellow precipitate, which is soluble in ligand excess and in some polar solvents. The results from elementary 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 measurements were used to determine the coordination number (<FONT FACE=Symbol>@</FONT> 3.0) and overall formation constant betaMLn (<FONT FACE=Symbol>@</FONT> 4 x 10(16)), of the lead complexes with ammonium diethanoldithiocarbamate, which show a good agreement with previous potentiometric results for the same system. A kinetic-spectrophotometric study was carried out in order to establish the decomposition of these complexes in acid medium.