Rhodium tertiary amides

In the commercial flow sheets, these elements are left in the aqueous raffinate after platinum and palladium extraction. Indium can be extracted in the -l-IV oxidation state by amines (see Fig. 11.11), or TBP (see Figs. 11.10 and 11.12). However, although the separation from rhodium is easy, the recovery of iridium may not be quantitative because of the presence of nonextractable iridium halocomplexes in the feed solution. Dhara [37] has proposed coextraction of iridium, platinum, and palladium by a tertiary amine and the selective recovery of the iridium by reduction to Ir(III). Iridium can also be separated from rhodium by substituted amides [S(Ir/ Rh) 5 X 10 ). 

Three types of product can be obtained from the reaction of amines with carbon monoxide, depending on the catalyst. (1) Both primary and secondary amines react with CO in the presence of various catalysts [e.g., Cu(CN)2, Me3N-H2Se, rhodium or ruthenium complexes] to give V-substituted and V,A-disubstituted formamides, respectively. Primary aromatic amines react with ammonium formate to give the formamide. Tertiary amines react with CO and a palladium catalyst to give an amide. (2) Symmetrically substituted ureas can be prepared by treatment of a primary amine (or ammonia) with CO " in the presence of selenium or... 

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