Determination of Stability Constants of UO2(II) Complexes with Thio Compounds by pH Metry

Abstract

The proton-ligand dissociation constant, log K_L of sodium pentamethylene dithiocarbamate (Pipdtc), diethyl dithiocarbamate (Dedtc), ammonium pyrrolidine dithiocarbamate (Apdtc) and potassium ethyl xanthate (Xanthate) and metal-ligand stability constants log K₁ and log K₂ of their metal complexes with UO₂(II) have been determined in 60% ethanol-water medium at 28ºC using Bjerrum Calvin pH titration technique as modified by Irving and Rosotti. The results obtained are compared with the data obtained for the other metal complexes of these ligands studied earlier in these laboratories. It was found that the proton ligand dissociation constants of these structurally similar thio compound and stability constants of their metal complexes decrease in the following order:

                                                Pipdtc > Dedtc > Apdtc > Xanthate