Green salt of Magnus

The first ammino-derivative of palladium was prepared by Vauquclin in 1813.1 Vauquelin s salt, the chloropalladite of tetranunino-palladium, [Pd(NH3)4]PdCl1, corresponds to the green salt of Magnus, the first known compound of the ammino-platinum salts. 

The chloroplatinate, [Pt(NH3)4Cl2]PtCl6, is obtained by mixing solutions of sodium chloroplatinate and dichloro-tetrammino-platinic nitrate, or by the prolonged action of chlorine on either the green salt of Magnus or the preceding salt suspended in -water. It crystallises in brilliant yellow prisms which are soluble in hot water. Hydrochloric and nitric acids precipitate the chloride and the nitrate respectively.2... 

Hydroxo - chloro - tetrammino - platinic Nitrate, [Pt(NH3)4 (0H)C1](N03)2, was first obtained by Raewsky 3 by the action of excess of nitric acid on the green salt of Magnus hence it is referred to as the nitrate of Raewsky. 

Magnus green salt takes its name from its discoverer (1828), H.G. Magnus, Professor of Physics and Technology at the University of Berlin. Pink [Pd(NH3)4]PdCl4, Vauqelin s salt, was discovered slightly earlier (1813) by L.-N. Vauquelin, Professor of Chemistry at the College de France. 

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. 

Other square planar Pt(II) complexes able to form infinite unidirectional chains in the solid state are known, in particular the Magnus s green salt [Pt(NH3)4][PtCl4],u but also Pt(I) complexes such as [Pt(bipy)2](N03) 2FI20 (obtained by electrochemical reduction of [Pt(bipy)2](NC>3)2 H20) have recently shown linear chain crystals (Pt-Pt = 3.56 A).12... 

Rundle and others (7, 105, 217) have suggested that the interaction between the metal atoms in these compounds is bonding, and that it is largely responsible for the uptake of the structure. So far as the analogues of Magnus s green salt are concerned, it has been shown that the structure... 

Jorgensen and Sorensen (Zeitsch. anorg. Chem., 1906, 48, 441) describe a red modification of Magnus green salt, which is probably a polymer of the usual green form. 

The chloroplatinite, [Pt (NH 3) 4C12]PtCl 4, may be prepared by the action of chloroplatinic acid on tetrainmino-platinous chloride, or by the action of chlorine on Magnus green salt suspended in boiling water. It is a red crystalline substance which is only7 slightly7 soluble in water. Silver nitrate transforms the salt into a mixture of silver chloroplatinite and dichloro-tetrammino-platinic nitrate. 

Magnus Green Salt (MGS) contains chains of alternating [Pt(NH3)4]2+ cations and [PtCl4]2-anions with a Pt—Pt separation of 3.245 A. Early reports of high electrical conductivities have... 

In general, intensely-colored Pt compounds owe this feature to intervalence CT transitions, hence to the presence of Pt in different oxidation states. Provided the solid state structure is favorable, a tiny deviation (< 1 %6) from an integral oxidation number can be sufficient to cause the phenomenon of color. For example, the famous Magnus Green salt, usually formulated as... 

Figure 6. Absorption spectrum of Magnus Green Salt, PtfNH jPtCl with polarized light...

Tetraamminepalladium(II) tetrachloropalladate(II), the palladium analog of Magnus green salt, [Pt(NH3)4][PtCl4], may be prepared by treatment of aqueous ammonium tetra-chloropalladate(II) with aqueous ammonia, by addition of aqueous ammonia to a palladium(II) chloride solution, by treatment of aqueous tetraamminepalladium(II) chloride with palladium(II) chloride solution, and by precipitation on mixing a freshly prepared solution of a tetra-amminepalladium(II) salt with cold aqueous potassium tet-... 

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