Electrochemical reduction of gallium(III) in non-aqueous solvents, assisted by 2,2'-bipyridine.

The electrochemistry of gallium(III) perchlorate in dimethylsulfoxide (DMSO) and acetonitrile (MeCN) at a mercury drop electrode is described and compared to that in water. The reduction of 2,2'-bipyridine (DIPY) and its interaction with free protons in the solvents mentioned is also surveyed. The electrochemistry of tris-(2,2'-bipyridine) gallium(III) perchlorate was studied in DMSO and MeCN. A gallium metal deposit is obtained by reduction of the complex compound in the first solvent, whereas lower valence gallium-DIPY species are obtained in the second. The existence of different catalytic prepeaks in DMSO is described. The first catalytic peak, which renders a metal deposit, is studied in detail, together with the possible interference of oxygen and free protons. These studies serve the basis of future development of an analytical procedure for the determination of trace concentrations of gallium.