Gold-Germanium Compounds

The chemistry of compounds with gold-germanium bonds has developed considerably since Schmidbaur and coworkers reported the first derivatives obtained by the insertion reaction of GeCl2 (as its dioxane complex) into a gold-halogen bond [75]. Both neutral and ionic compounds have been reported and a larger structural diversity in comparison with the silicon analogs has been established (Table 4.4). 

The dithizone method has been applied in the determination of zinc in sewage [89], cadmium and its compounds [31], aluminium [90,91], nickel [11], cobalt [12], gold [92], germanium compounds [37], and tellurium [93]. Zinc was determined with dithizone in aqueous media in the presence of dodecyl sulphate using the FIA technique [94]. 

Phillips and Timms [599] described a less general method. They converted germanium and silicon in alloys into hydrides and further into chlorides by contact with gold trichloride. They performed GC on a column packed with 13% of silicone 702 on Celite with the use of a gas-density balance for detection. Juvet and Fischer [600] developed a special reactor coupled directly to the chromatographic column, in which they fluorinated metals in alloys, carbides, oxides, sulphides and salts. In these samples, they determined quantitatively uranium, sulphur, selenium, technetium, tungsten, molybdenum, rhenium, silicon, boron, osmium, vanadium, iridium and platinum as fluorides. They performed the analysis on a PTFE column packed with 15% of Kel-F oil No. 10 on Chromosorb T. Prior to analysis the column was conditioned with fluorine and chlorine trifluoride in order to remove moisture and reactive organic compounds. The thermal conductivity detector was equipped with nickel-coated filaments resistant to corrosion with metal fluorides. Fig. 5.34 illustrates the analysis of tungsten, rhenium and osmium fluorides by this method. 

By and large, of the 86 naturally occurring elements in nature, some 20 or so are deemed to be essential as trace elements and approximately 10 are envisaged as toxic. Most of these essential trace elements are metals and are able to form simple ionic compounds or complex coordination compounds. However, some of the metallic elements such as cobalt, palladium, platinum, gold, mercury, germanium, tin, lead. 

The Ag-DDTC method was used for determination of arsenic in waters [42,47,78-80], plant materials [41,48], food products [82], sewage and sediments [83], iron ores [44], cast iron and steel [45,84], copper and its salts [22,45], silver and gold [85], high purity reagents [21,46], germanium dioxide [86], hydrofluoric acid [87], phosphorus compounds [88], and sulphur 89]. 

The chemistry of organic germanium, tin and lead compounds The chemistry of dienes and polyenes The chemistry of organic derivatives of gold and silver UPDATES... 

---