POTENTIOMETRIC AND POLAROGRAPHIC STUDIES OF THE STABILITY OF LEAD(II) COMPLEXES WITH 2,2'-DIPYRIDYL

The stability constant of the Pbdipy2+ complex was estimated by the potentiometric method, which is based on the use of a reversible electrode of lead amalgam. The same constant was determined from the dependence of the half-wave potential of the reversible polarographic wave, which resulted from the reduction of dipyridyl complexes of lead(II), upon the concentration of the 2,2'-dipyridyl. The absence of specific adsorption of lead(II) complexes explains the absence of a complicating influence of the 2,2'-dipyridyl molecules adsorbed at the mercury electrode on the polarographic wave of reducing Pbdipy complexes.