Patent GB-782465-A (GB)
Title: Improvements in complex hydroxides
IPC: C01G55/00
Filed: 1955-05-25
Abstract: Complex platinum or palladium hydroxides in which the metal is in the form of a complex cation are prepared by passing an aqueous solution of the corresponding complex platinum or palladium salt over an anion-exchange resin whilst the resin is in the hydroxyl cycle.  The platinum or palladium salts consist of platinous salts of general formula [Pt(A)4]R2, where A is NH3, H2O, pyridine, aniline, NH2OH, or CH3NH2, or combinations thereof and R is the chloride, bromide, iodide, nitrate, nitrite or sulphate, for example platinous tetrammino chloride; the platinous acido salts of general formula [Pt(A)3R]R, for example [Pt(NH3)3-(OH)]Cl; the platinic salts [Pt(A)6]R4, for example platinic hexamminochloride and the platinic diacido and triacido salts. The anion exchange resin is preferably the reaction product of tertiary amines with haloalkylated vinyl aromatic hydrocarbon copolymers, for example "Amberlite" (Registered Trade Mark). According to examples, (1) an anion exchange resin was converted to hydroxyl form by a 10 per cent sodium hydroxide solution and washed with distilled water.  A 0.022 molar solution of platinous tetramminochloride was percolated through the resin at 5 c.c. per minute.  The resulting aqueous solution of platinous tetramminohydroxide may be treated with ethyl alcohol to precipitate the tetramminohydroxide as a crystalline solid which may be dried at room temperature out of contact with air; (IV) ammonium hydroxide was added to aqueous chloroplatinic acid solution in a mol. ratio of more than eight to one and the precipitate formed dissolved by agitation and mild heating.  The solution consisted of a mixture of platinic ammine complex chlorides including [Pt(NH3)6]-Cl5, [Pt(NH3)5(H2O)]Cl4, [Pt(NH3)4(H2O)2]Cl4.  An aqueous solution of these complex chlorides of 0.0214 molar concentration was percolated through an anion exchange resin in the hydroxyl cycle thereby converting the chloride to the hydroxide; (VII) a 0.4 molar solution of palladous chloride was reacted with excess ammonium hydroxide solution and the mixture heated to 160 DEG  F. with agitation to obtain a solution of palladous tetrammino - chloride, which at a concentration of about 0.03 molar was passed through an anion-exchange resin mass.  The resulting solution of palladous tetramminohydroxide was freed from ammonia by heating.ALSO:Complex platinum or palladium hydroxides in which the metal is in the form of a complex cation are prepared by passing an aqueous solution of the corresponding complex platinum or palladium salt over an anion exchange resin whilst the resin is in the hydroxyl cycle.  The platinum or palladium salts consist, for example, of the platinous salts of general formula [Pt(A)4]R2 where A is NH3, H2O, pyridine, aniline, NH2OH or CH3NH2, or combinations thereof and R is the chloride, bromide, iodide, nitrate, nitrite or sulfate; the platinous acido salts of general formula [Pt(A)3R]R; the platinic salts [Pt(A)6]R4 and the platinic diacido and triacido salts.  The anion exchange resin is preferably the reactive product of tertiary amines with haloalkylated vinyl aromatic hydrocarbon copolymers for example "Amberlite" (Registered Trade Mark).