Platinous salts

Platini-rhodanwasserstoffsaure, /. thiocyano-platinic acid, thiocyanoplatinic(IV) acid, -salz, n. platinic salt, specif, platinum (IV) salt, -selencyanwasserstoffsaure, /. selen-ocyanoplatinic acid, selenocyanoplatinic(IV) acid, -verbindung, /. platinic compmmd, specif, platinum (IV) compoimd. 

Pd(NH3)2R2], and the pallado-diammines or tetramraino-palladium salts, [Pd(NH3)4]R2. These are analogous to two of the series of the aminino-derivatives of the platinous salts, the platos-aramines and the plato-diammines. 

Ammino-derivatives of the unstable palladic salts are unknown, but a series of compounds have been prepared where pyridine takes the place of ammonia in the complex, and these appear to be derivatives of palladic salts. Unlike the platinic salts, however, the co-ordination number in these substances is four instead of six. 

Tetrammino-platinous salts, plato-diammine salts. 

Acido-trianvmino-platinous salts, plato-monodiammine salts. 

Diacido-diammino-platinous salts, platos-ammines or plato-semi-... 

Triaddo-ammino-platinous salts, plato-semi-ammine compounds. 

Diacido-tetrammino-platinic salts, platini-diammine compounds. 

Triacido-triammino-platinic salts, platini-monodiammine com-... 

Tetrammino-platinous salts are known containing pyridine in place of ammonia. Thus, diammino-dipyridino-platinous salts have been prepared. These salts are interesting, as they exist in isomeric forms, and through them the configuration of the isomeric diacido-diammino-platinous compounds have been determined. It is well known that diacido-diammino-platinum exists in stereo-isomeric forms. These isomers react with two molecules of pyridine in such a manner that pyridine replaces acidic radicles in the complex with formation of diammino-dipyTidino-platinous salts. Depending upon which isomer is treated with pyridine, two different diammino-dipyridino-platinous salts are produced. Cis- or unsymmetrical dichloro-diammino-platinum is... 

Aquo-triammino-platinous salts have been described of general formula [Pt(NH3)3HsO]R2. These are prepared by passing a current of air through a solution of diammino-dihydroxylamino-platinous chloride, [Pt(NH3)2(NH2OH)2]Cl2, containing ammonia and ammonium sulphate and a small quantity of any copper salt. Oxidation takes place, and a colourless crystalline precipitate is obtained which is soluble ill warm dilute sulphuric acid. Analysis of this product indicates that it is probably a diplatinum derivative of composition... 

These substances are obtained by heating the corresponding tetrani-mino-platinous salts. They dissolve in aqueous ammonia until reformation of the tetrammino-salts, and they can take up two atoms of chlorine yielding the corresponding platinic compound thus ... 

Both series of compounds easily add on halogen, passing into the corresponding platinic derivatives. The configuration of the compounds is established by their behaviour on the addition of pyridine, as already explained under the tetrammino-platinous salts (sec p. 228). 

In the annnino-platinous compounds there is, as in the other amniino-metallic compounds, a complete transition series from tetrammino-platinous salt to tetra-acido-platinous salt for example, tetrammino-platinous chloride, [Pt(NH3)JC12, chloro-triammino-platinous chloride, [Pt(NH3)3Cl]Cl, dichloro-diammino-platinum, [Pt(NH3)2Cl2], trichloro-ammino-platinous salt, [Pt(NH3)Cl3]K, and potassium chloropiatinite, [PtCl6]K2, where all the ammonia is replaced by chlorine. Comparing the molecular conductivities, the first-mentioned compound has conductivity at 1000 litres dilution of 260, the next 115-8 in the third compound the conductivity drops almost to zero, the fourth has conductivity of 106-8, and the last salt has conductivity of 267.2... 

These are represented by the chloro-pentammino-platinic salts. This series is difficult to prepare, but the chloro-deriva tives may be obtained by the action of liquid ammonia on ammonium chloro-platinate, [PtCl6](NH4)2, in absence of water in a sealed tube at ordinary temperature. 

All the salts may be reduced by means of zinc and dilute hydrochloric acid, yielding the corresponding tetranunino-platinous salts.2... 

This series of compounds is formed by the action of halogen or nitric acid on tetrammino-platinous salts, or by the addition of ammonia to tetracido-diammino-platinuni compounds. 

A series of dihydroxo-tetrammino-platinic salts, [Pt(NH3)4(OH)2]R2, has been investigated by Carlgreen and Cl eve.1 They are produced by oxidising tetrammino-platinous salt with hydrogen peroxide. 

These salts are obtained from the acido-triammino-platinous salts by oxidation. 

The series is represented by the potassium salt and the tetrammino-platinous salt. 

Ammino-derivatives of Platinum Salts—Derivatives of Platinous Salts— Derivatives of Platinio Saits—Derivatives containing Hydroxylamine and Hydrazine in place of Ammonia—Symmetrical and Asymmetrical Compounds—Diplato-animino-salts—Diplati-ammino-salts. 

Both the dry complex oxalate and its aqueous solution are unstable to direct light and deposit yellow ferrous oxalate. This property was formerly utilized in platinotypes—a photographic process by which the FeCaO produced by illumination reduces a platinic salt to a black platinum image. The oxalate is a mixture, which has been resolved into its mirror images. 

Table 2 Partially Oxidized Bis(oxalato)platinate Salts...

The partially oxidized bis(oxalato)platinate salts of monovalent cations are often characterized by the existence of several crystalline phases each with very similar stoichiometry. This is particularly true for the potassium salts. Four crystalline phases of stoichiometry Kt6i0.04[Pt(C2O4)2]-xH2O (a-, P-, 5- and e-KOP) are known plus K] sitPt O J HjO (y-KOP).63... 

A characteristic feature of these partially oxidized bis(oxalato)platinate salts of divalent cations is the coexistence of two modulations of the lattice over a wide temperature range (a) a one-dimensional modulation, as detected by the appearance of diffuse lines on X-ray films, perpendicular to the [Pt(C204)2] anion stacking direction and surrounding the even Bragg reflection layer lines of non-zero order (b) a three-dimensional modulation which gives rise to a complicated pattern of fine satellite spots in the neighbourhood of every reciprocal layer line. 

Figure 6 Variation of electrical conductivity with inverse temperature for a series of bis(oxalato)platinate salts...

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