Magnus green salt

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. 

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-... 

Magnus green salt, the first platinum ammine, was discovered in 1828.)... 

Metal chain substances containing alternating cations and anions e.g., Magnus green salt, [Pt(NH3)4][PtCU], or [Pt(CNCH3)4][Pt(CN)4], are prepared by slow mixing of the component square-planar complex ions and are not discussed here. 

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). ... 

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