Cathodic Action of the Uranium Chelate Compounds at the Dropping Mercury Electrode. II. Uranyl‐Glutamate Complex

The polarographic behavior of a tridentate chelate compound of uranyl‐glutamate has been investigated over the p H range of 1.5 to 5.5. The first wave of one‐electron reduction and diffusion‐controlled reversible wave was applied through this p H. range. Below p H 1.9 there was no chelation, and above p H 5.5 turbidity ensued. At p H 3.0 to 3.9 the diffusion current was independent of p H value and the diffusion current constant was calculated to be 2.08. The proportionality between uranyl ion concentration and diffusion current held within the narrow range of 2.2 × 10 −4 M to 3.3×10 −3 M with 1.9% average deviation of the mean. The chelate forms and electrode reactions identified from the half‐wave potential and diffusion current data were:\documentclass{article}\pagestyle{empty}\begin{document}$ \begin{array}{*{20}c} {p{\rm H}} \hfill & {4.4 - 5.5,} \hfill & {{\rm UO}_2 \left({\rm G} \right)_2 = + e = {\rm UO}_2 ^ + + 2{\rm G}^ =} \hfill \\ {p{\rm H}} \hfill & {3.0 - 4.4,} \hfill & {{\rm UO}_2 \left({{\rm HG}} \right)_2 + {\rm H}^ + + e = {\rm UO}_2 \left({{\rm HG}} \right) + {\rm H}_2 {\rm G}} \hfill \\ {p{\rm H}} \hfill & {< 1.9,} \hfill & {{\rm UO}_2 ^{+ +} + e = {\rm UO}_2 +} \hfill \\\end{array} $\end{document}