Cadmium complexes imides

If N,N-ethylenediglycine is present, e.g. in industrial ethylene-diaminetetraacetic acid, the wave of its cadmium complex under the given conditions is only OT V more positive than the wave for cadmium-nitrilotriacetic acid complex, and the resolution is thus difficult. Consequently, in the analysis of such mixtures the sum of the wave heights of the cadmium chelates of nitrilotriacetic acid and N,N-ethylenediglycine is first measured. The sample is then treated with hydrochloric acid to adjust the pH-value to 1 5-2-0 and boiled for 20 min. The cyclic imide formed from N,N-ethylenediglycine according to the reaction... 

The zinc and cadmium tellurolato complexes are air-sensitive polymeric solids14 which should be handled under inert gas. They are sparingly soluble in petroleum and chlorocarbons but readily dissolved by coordinating solvents (N,AT-dimethylformamide, dimethylsulfoxide, or pyridine). Zn(TeAr)2 forms a crystalline 1 2 adduct with 2-methyl-lH-imidazole, Zn(TeAr)2(imid)2. Heating solutions of Zn(TeAr)2 and Cd(TeAr)2 in mesitylene leads to formation of ZnTe and CdTe, respectively. H NMR Zn(TeAr)2 (DMSO-d6) <5 2.1 (s, 3H), 2.4 (s, 6H), 6.8 (s, 2H) Cd(TeAr)2 (pyridine-d5) 5 2.13 (s, 3H), 2.3 (s, 6H), 6.72 (s, 2H). 

A method for extracting cadmium, copper, europium, and nickel metal ions from aqueous solution using modified polyethyleneimine is described. The polymer modification consists of grafting an imide, diol, triol, carboxylic acid, or thiocar-boxylic acid function to poly(ethyleneimine), which then forms stable metal complexes that are readily removed from solution. 

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