Tetrachloroplatinate salts

Solubility tests in absence of Ti02 were first performed with a lO M solution of platinum prepared from an ammonium tetrachloroplatinate salt. However, upon mixing NaOH and lO M (NH4)2PtCl4 no precipitation was initially observed. At room temperature, the formation of a precipitate becomes nonetheless detectable after 24 h stirring. After 48 h precipitate was still forming. In m effort to obtain a complete precipitation in a reasonable time, an attempt was made to hydrolyze at 60°C. At this temperature, precipitate formation... 

Angeloni, A. Orpen, A.G. Control of hydrogen bond network dimensionality in tetrachloroplatinate salts. Chem. Cornmun. 2001. 343-344. 

In the complex [Co(NH3)6]Cl3, the cation is [Co(NH3)6]3+, and it is named first. The coordinated ammonia molecules are named as ammine, with the number of them being indicated by the prefix hexa. Therefore, the name for the compound is hexaamminecobalt(III) chloride. There are no spaces in the name of the cation. [Co(NH3)5C1]C12 has five NH3 molecules and one CN coordinated to Co3+. Following the rules just listed leads to the name pentaamminechlorocobalt(III) chloride. Potassium hexacyanoferrate(III) is K3[Fe(CN)6j. Reinecke s salt, NH4[Cr(NCS)4(NH3)2], would be named as ammonium diamminetetrathiocyanatochro mate (III). In Magnus s green salt, [Pt(NH3)4][PtCl4], both cation and anion are complexes. The name of the complex is tetraammineplatinum(II) tetrachloroplatinate(II). The compound [Co(en)3](N03)3 is named as tris(ethylenediamine)cobalt(III) nitrate. 

The compound does not have any notable commercial applications. It is used to prepare tetrachloroplatinic(ll) acid (choroplatinous acid) and tetra-chloroplatinate salts. 

The original method1 of preparation of Zeise s salt, K[Pt(C2 H4 )C13 ]-H20, and subsequent modifications thereof2-4 all require either prolonged reaction times (7-14 days) or the use of high pressures. Furthermore, these procedures tend to yield products contaminated with potassium chloride and unreacted potassium tetrachloroplatinate(II). The improved procedure described below, which utilizes tin(II) chloride to catalyze the reaction between ethylene and the tetrachloroplatinate(II),5,6 results in the formation of Zeise s salt of high purity and in high yield within a few hours at atmospheric pressure. 

A solution of 20.8 g. (55 mmoles) of potassium tetrachloro-platinate(II) in 100 ml. of water is prepared in a 250-ml. suction flask with a nitrogen flow through the sidearm to provide an inert atmosphere. (The procedures work equally well at halfscale.) Triethylphosphine (15 ml., 100 mmoles) is added all at once and the mixture is stirred with a magnetic stirrer at room temperature for one hour. A pink-tan precipitate of tetrakis-(triethylphosphine)platinum(II)tetrachloroplatinate(II) forms. The mixture is heated on a steam bath for one hour. The pink salt dissolves, and a layer of pale yellow dichloro-bis(triethyl-phosphine)platinum forms on the liquid. The solid is filtered, washed with water, crushed in a mortar, and dried under... 

NH4)2(PtCU), H2(PtCl6)] are responsible for this sensitivity. The bromide and iodide compounds are less effective. These platinum compounds form a platinum-protein conjugate that is the true allergen. Tetrachloroplatinates are mutagens. This seems to be true only of complex platinum salts. It does not apply to the complex salts of the other precious metals. Platinum amine nitrates and perchlorates either detonate when heated or are impact-sensitive. 

Aqueous zinc nitrate similarly treated gave the colorless crystalline bis (triaminopropane) zinc di-iodide (X) (20). An aqueous solution of sodium tetrachloroplatinate(II), Na2[PtCl4], when treated with two equivalents of the triamine, heated until clear, and then concentrated and added to aqueous sodium bromide and iodide gave the colorless bis(triamino-propane)-platinum(II) dibromide (XI X = Br), m.p. 270-271°C., and the di-iodide (XI X = I), m.p. 266-267°C., respectively. The fact that in these salts (which were sufficiently stable for recrystallization from hot water) the divalent platinum was showing the exceptional coordination number of 6—i.e., that it was coordinated to all six amino groups of the two triamine molecules, was shown by the addition of the dibromide to an excess of sodium picrate, both in cold aqueous solution, whereby only the dipicrate (XI X = C6H2N3O7) was precipitated had any amino groups remained uncoordinated, they also would have formed picrates (1928) (19). 

The analogous platinous salt, XV, was subsequently (1928) obtained by treating potassium tetrachloroplatinate(II), K2[PtCl4], in hot aqueous solution with triaminopropane trihydrochloride. This salt was converted... 

This base (as the trihydrochloride) reacted with hexachloroplatinic(IV) acid to form the salt, XXXIV, in which the central nitrogen atom becomes asymmetric attempts to resolve it not unexpectedly failed as this group would almost certainly have very low, optical stability. The salt, XXXIV, when treated with silver salts, lost hydrogen chloride with the formation of the salt, XXXV. With potassium tetrachloroplatinate(II), the salt, XXXVI (X = Cl), was obtained and was more readily isolated after treatment in solution with sodium bromide or iodide as the cream-colored XXXVI (X = Br) or XXXVI (X = I), respectively. The free base reacted with aquopentamminocobaltic trichloride to give the... 

The methods previously reported for the preparation of tetrachloroplatinic(II) acid1 and platinum(II) chloride are laborious and difficult to control. Platinum(II) chloride has been prepared by the thermal decomposition of ammonium hexachloroplatinate(IV)2 or of anhydrous platinum-(IV) chloride.3 According to a recent report,4 hydrazine sulfate is an effective reducing agent for the preparation of tetrachloroplatinate(II) salts from the corresponding hexachloroplatinate(IV) salts. This procedure has been extended to the preparation of aqueous tetrachloro-platinic(II) acid and solid platinum (II) chloride. 

According to Chariot [11], PtJ CU should be very easily hydrolyzed and the hydroxide of Pt is almost not soluble in NaOH solution. Preparations of Pt/Ti02 catalysts by the deposition-precipitation method with a tetrachloroplatinate (II) containing salt were thus investigated. 

CHRONIC HEALTH RISKS repeated exposure to soluble platinum salts may cause symptoms of platinum allergy, including rhinitis, conjunctivitis, asthma, urticaria, and contact dermatitis may cause lymphocytosis, tetrachloroplatinates are reported to be mutagens. 

Other methods for the preparation of the cis isomer include heating the trans isomer or tetraammineplatinum-(II) chloride with aqueous ammonia and reaction of ammonium carbonate with tetrachloroplatinic(II) acid. Other methods for the preparation of the trans isomer include the action of hydrochloric acid on dihydroxodiammineplatinum-(II) and the thermal decompositions of ammonium tetra-chloroplatinate(II), tetraammineplatinum(II) chloride, or tetraammineplatinum(II) tetrachloroplatinate(II) (Magnus green salt). ... 

Magnus s green salt — see Platinum, tetraammine-, tetrachloroplatinate... 

The preparation of compounds of platinum(II) usually involves a preliminary preparation of platinmn(IV) compounds. For example, the sjmthesis of metal salts by treating a solution of tetrachloroplatinic(II) acid mth carbonates or chlorides requires the preliminary preparation of the acid by reducing hexachloroplatinic(IV) acid with a suitable reagent such as sulfm dioxide. Otherwise, a metallic hexachloroplatinate(IV) may be reduced to the corresponding tetrachloroplatinate(II) by sxilfur dioxide, potassium oxalate, potassium hydrogen sxil-fite, hydrogen sulfide, potassium hypophosphite, or copper(I) chloride. ... 

Potassium tetrachloroplatinate(II) is somewhat soluble in water (0.93 g./lOO ml. water at 16° and 5.3 g./lOO ml. at 100°). It is almost insoluble in alcohol but when in contact with alcohol undergoes reduction. The dry salt and aqueous solutions are completely stable in hght. The crystals are dark red or brownish red and furnish a convenient starting point for many platinum(II) derivatives. 

Tetrammineplatinum(II) chloride may be prepared by heating any one of the following with excess aqueous ammonia until a colorless solution results platinum(II) chloride tetrammineplatinum(II) tetrachloroplatinate(II) (Magnus s green salt), [Pt(NH3)4][PtCl4] diamminedi-chloroplatinum, [Pt(NH3)2Cl2] or a solution of tetra-chloroplatinic(II) acid. The present method involves the preparation of pure tetrammineplatinum(II) tetrachloro-platinate(II) and its subsequent reaction with aqueous ammonia. 

---