Platinum II Chloride

Submitted by GEORGE T. KERR and ALBERT E. SCHWE1ZER Checked by THEODORE DEL DONNOt 

Commercial dihydrogen hexachloroplatinate(lV) of high purity is now readily available (for a platinum assay of 40.0%, x is 2.32 in the above equation). The acid, 10 g, is spread into a thin layer less than 5-mm thick in a combustion boat and a steady air purge is maintained (200 mL/min) through a combustion tube of approximately 1 L in volume. The temperature of the furnace is raised from 25 to 350° in 50° steps over a period of 3 hours. The temperature is held at 350° for 0.5 hours. The sample can then be removed from the furnace and stored in a desiccator. The yield is quantitative based on the Pt assay of the dihydrogen hexachloroplatinate(IV) used ( 98% ). 

A small portion of sample can be tested for purity by heating in a stream of hydrogen at 150° to yield platinum metal. Anal. Calcd. for PtCl2 Pt, 73.3 Cl, 26.7. Found Pt, 73.5, 73.2 Cl, 26.8.  

Prepared in this manner, j3-platinum(ll) chloride is a chocolate-brown, nonhygro-scopic solid with sufficient porosity to chemisorb several small molecules.5-7 Although practically insoluble in water, it reacts with hydrochloric acid to form dihydrogen tetrachloroplatinate(ll) and with ammonium hydroxide to form tetraammineplatinum(ll) chloride. It is sensitive to high concentrations of ammonia, undergoing reduction to metallic platinum.7 

H2PtCl6-6H20 PtCL + 2HC1 + 6H20 PtCl PtCl2 + Cla 

Berzelius1 prepared platinum(II) chloride by evaporation of a solution of hexachloroplatinic(IV) acid and heating of the residue to about 300 to 350° with constant stirring. This method has been more recently modified by Kharasch and Ashford.2 Nilson3 obtained a more pure product by evaporation of a solution of tetrachloroplatinic(II) acid. The preparation of pure platinum (II) chloride from readily obtainable hexachloroplatinic(IV) acid 6-hydrate is given here. This is an adaptation of the method of Wohler and Streicher.4 

X The directions of pages 253 and 254 are followed to the next-to-last sentence The pulverized material is again.. . Then the directions above are continued from that point. 

A small portion of the product is tested for any unreacted platinum(IV) chloride by leaching with a few drops of hot water. An equal volume of a saturated solution of ammonium chloride is added to the leach water, and if there is no precipitate within 1 minute the product is pure. If a precipitate appears, the entire product should be leached with water until free of the soluble platinum(IY) chloride. The purified product is partially dried by suction filtration and finally completely dried by a drying agent in a desiccator. The yield is 2.8 g. (91% based on H2PtCl6-6H20). Anal. Calcd. for PtCl2 Pt, 73.3 Cl, 26.6. Found Pt, 73.0 Cl, 26.8.  

Platinum(II) chloride prepared by this method is a brownish-green, nonhygroscopic powder, practically insoluble in water but soluble in hydrochloric acid to form tetra-chloroplatinic(IV) acid by disproportionation. 

Submitted by William E. Cooley and Daryle H. Busch Checked by L. C. Drake and P. G. Waldo  

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. 

Ten and six-tenths gramsj of pure hexachloroplatinic(IV) acid 6-hydrate (0.0205 mol) is dissolved in 50 ml. of water in a 150-ml. beaker. One and seven-hundredths grams of solid hydrazine dihydrochloride (0.0103 mol) is added in small portions to the solution. Each addition is followed by effervescence, which soon subsides. The total time of addition is about 5 minutes. The resulting cherry-red solution is placed on a steam bath and warmed until bubbling stops. Any traces of finely divided platinum (platinum black) which are present are then removed by filtration. The red solution is evaporated to dryness on a steam bath with the aid of a stream of air. The 

The platinum content is determined by igniting a 1-g. sample in a weighed crucible. For determination of chloride, 0.5 g. of the sample is placed in a 100-ml. beaker with 35 ml. of water and 10 ml. of 15 N aqueous ammonia. About 0.5 ml. of 16 N nitric acid is added, and the mixture is heated with occasional stirring until solution is complete. The solution is treated with 1 g. of silver nitrate dissolved in 5 ml. of water and with sufficient 16 N nitric acid to render it definitely acidic. The suspension is warmed to coagulate the precipitated silver chloride and filtered. The residue is dried at 110° and weighed. Anal. Calcd. for PtCl2 Pt, 73.35 Cl, 26.65. Found Pt, 72.65, 73.19,f 72.85, f 73.40 f Cl, 26.89, 26.63, f 26.88, f 26.80. f 

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Ethene can add on to certain metal salts it is believed that the extra electrons of the double bond can be donated to some extent an example is the compound PtCl2-C2H4 formed with platinum(II) chloride which has the structure... 

Platino-. platinous, platino-, platinum (II). -chlorid, n. platinous chloride, platinum(II) chloride, -chlorwasserstoff, m., -chlorwasserstoffsaure, /. chloroplatinous acid, chloroplatinic (II) acid. -cyanwasserstoff, m., -cyanwasserstoffsaure, /. cyanoplatinous acid, cyanoplatinic (II) acid, platinocyanic acid, -rhodanwasserstoffsaure, /. thiocya-noplatinous acid, thiocyanoplatinic(II) acid. 

As is the case of tetrasubstituted phthalocyanines, a mixture of four structural isomers is obtained if the 5,6-substituents of isoindolinediimine are different. For example, 5-ethoxy-6-octyl-oxyisoindolinediimine, when treated with platinum(II) chloride in refluxing 2-(dimethylamino)-ethanol under nitrogen for 12 hours, yields a mixture of the corresponding isomeric piatinum(II) phthalocyanines in a yield of 28 %.117... 

C22H34N12O10Pt2+-1.5 Cl- 0.5 I--2 H20 ranosyl]-6-(dimethylamino)purine, dihydrochloride, pentahydrate (puromycin, dihydrochloride, pentahydrate) Ethylenediamine-bis(guanosine) platinum(II), chloride, EGUOSP 34 375... 

Approximately 2 g. of shredded asbestos slurried in 15 ml. of water is added to a solution containing 10 g. of sodium formate in about 30 ml. of water the solution is boiled gently, then about 80 ml. of a 5% platinum(II) chloride solution is added. The solution is boiled until the platinum has been deposited. 

Nucleophihc attack of methoxide ion on olefinic and acetylenic groups of suitable unsaturated phosphine complexes of platinum(II) takes place to give cyclic, a-bonded complexes. This reaction appears to occur whether or not the unsaturated group is coordinated to the metal (22). But-3-enyl diphenylphosphine forms a chelate complex with platinum(II) chloride which on treatment with sodium hydrogen car-... 

The ligand 2-allylpyridine is reported to form chelate complexes with copper(I) chloride, silver nitrate and platinum(II) chloride (29). Diphenyl vinylphosphine also forms stable 1 1 and 2 1 adducts with silver nitrate in which both the phosphorous and the double bond are thought to be coordinated to silver (30). 

A. CHLORO(2,2 6, 2"-TERPYRIDINE)PLATINUM(II) CHLORIDE DIHYDRATE, [Pt(terpy)Cl]Cl 2H2O... 

Dichloro(2,3-diamino-K2 N2,N3-N,N, N-trimethyl-1 -propanaminium)platinum(II) chloride... 

A series of di-, tn-, and tetrabromides is well known. Platinum(ll) iodide is precipitated as a black insoluble compound by the addition of 2 equiv of iodide to a hot solution of platinum(II) chloride. The black, insoluble, graphitelike substance, platiniim(TTT) iodide, is made by combining the elements in a sealed tube at 350°C. 

Similar results are obtained with platinum(II) chloride as catalyst, although in this case yields of (XXX) and (XXXII) are relatively low. 

A preparation of platinum (II) chloride by a different method appears in Vol. V of Inorganic Syntheses. 

Platinous compounds [see specific compounds under Platinum (II)] Platinum (II) chloride, 5 208 6 209 analysis of, 5 209 Platinum (IV) chloride, 2 253 Platinum (II) complex compounds, anions, with 1,4-butadiene, K2[Cl3PtC4H6PtCI3], 6 216 anions, with ethylene, [Pt(C2H4)-CU]K, 5 211, 214... 

A Pt(II)-bridged wire compound was prepared by Mayor et al. [18] by treating trans-bis(triphenylphosphane)platinum(II) chloride (63) with the alkyne 4 and Cul as catalyst (Scheme 10.20). The trans configuration of the product 64 was confirmed by X-ray crystallographic analysis. 

To a pale yellow solution of 0.739 g. (0.92 mmole) of a mixture of cis- and frans-dichlorobis(cyclohexyldiphenylphosphine)-platinum(II)t in 25 ml. of tetrachloroethane (technical grade) is added 0.292 g. (1.10 mmoles) of platinum(II) chloride. The mixture is gently refluxed (b.p. 146°C.) with continuous stirring for 60 minutes under an atmosphere of nitrogen. The mixture... 

Gay M, Montana AM, Moreno V, Prieto M-J, Perez JM, Alonso C (2006) Studies of interaction of trichloro r 2-cis-N, N-dimethyl-l-[6-(N , N -dimethyl-ammoniummethyl)-cyclohex-3-ene-l-yl]-methylammonium platinum(II) chloride with DNA effects on secondary and tertiary structures of DNA. Cytotoxic assays on human ovarian cancer cell lines, resistant and non-resistant to cisplatin. Bioorg Med Chem 14 1565-1572... 

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