Ammonium chloropalladite

Dickinson, R. G. The crystal structures of potassium chloroplatinite and of potassium and ammonium chloropalladites. J, Amer. Chem. Soc. 44, 2404-2411 (1922). 

Ammonium chloropalladite (0.1 mg. Pd/ml.). Dissolve 133.6 mg. of ammonium chloropalladite in 450 ml. of demineralized water acidified with 5 ml. of concentrated H2SO4. Dilute to 500 ml. Dilute this solution 1 1 before using as an internal standard. 

Acid Precipitation. Evaporate a measured portion of the sample to about 100 ml. or, if less than 100-ml. aliquots are used, adjust the final volume to about 100 ml. Add 3 ml. of the ammonium chloropalladite solution and 30 ml. of stannous chloride solution. Adjust the pH to 0.75 with 3N HCl and add 20 ml. of the thioacetamide solution. Cover the beaker with a watch glass, heat the sample to just below the boiling point, and allow it to stand overnight at room temperature. 

Add successively 3 ml. of ammonium chloropalladite solution, 30 ml. of indium sulfate solution, and 25 ml. of ammonium chloride solution. Adjust the pH of the solution to 7.2 with IN ammonium hydroxide and add successively 20 ml. of ammonium sulfite solution and 20 ml. of thioacetamide solution. Adjust the pH of the sample to 8.0 with IN ammonium hydroxide and allow the sample to stand overnight at room temperature. 

Method 1. Polymerization of Mercaptans with Metal Salts The earliest suggestion that monomercaptans yield polymers from reaction with metal salts was made by Mann and Purdie in 1935. The mercaptan was added to a chloroform solution of ammonium chloropalladite (IS). Red-orange solids were obtained from aliphatic mercaptans. The polymeric structure was proposed because the products did not conduct electricity. 

The work of Alfred Werner led to a considerable understanding of the stereochemistries of arrangements of ligands. This understanding was reinforced by X-ray diffraction studies of metal complexes, for example, in the determination of the structures of ammonium hexachloroplatinate and chloropalladite, shown in Figure 15.4. In these there are six groups around the metal ion, at an equal distance, rather like a small portion of the sodium chloride structure. 

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