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 po tentiometric method, which is based on the use of a reversible electro de of lead amalgam. The same constant was determined from the dependen ce of the half-wave potential of the reversible polarographic wave, wh ich resulted from the reduction of dipyridyl complexes of lead(II), up on the concentration of the 2,2'-dipyridyl. The absence of specific ad sorption of lead(II) complexes explains the absence of a complicating influence of the 2,2'-dipyridyl molecules adsorbed at the mercury elec trode on the polarographic wave of reducing Pbdipy complexes.