Ammines platinum

Platinum ammine complexes have been a fertile area for studying transinfluence. Table 3.21 lists data for a range of ammines showing how /(195Pt-15N) depends upon the trans-atom [153]. (A further selection of data can be found in R.V. Parish, NMR, NQR, EPR and Mossbauer Spectroscopy in Inorganic Chemistry, Ellis-Horwood, Chichester, 1991, pp. 76, 87.) Possibly the most detailed study (of complexes of tribenzylphosphine) examined over a hundred neutral and cationic complexes [154] (Table 3.22). 

Louis-Nicolas Vauquelin (1763-1829) discovered the pink compound tetraamminepalladium(II) tetrachloropalladate(II), [Pd(NH3)4][PdCl4].14 This compound, which contains coordinated palladium in both the cation and the anion, is still known as Vauquelin s Salt after its discoverer. The corresponding platinum compound, [Pt(NH3)4][PtCl4], was discovered by Heinrich Gustav Magnus (1802—1870).15 It constitutes the first discovered platinum ammine and is known as Magnus ... 

The next major theory of metal ammines was proposed by Carl Ernst Claus (1796—1864). In 1854, Claus rejected the ammonium theory and suggested a return to Berzelius view of complexes as conjugated compounds. He compared the platinum ammines not with ammonium salts nor with ammonium hydroxide but with metal oxides. He designated the coordinated ammonia molecule as passive, in contrast to the active, alkaline state in the ammonium salts, where it can easily be detected and replaced by other bases . 

A study of the platinum-ammines shows that a large number of them can be arranged in two well-defined series. One series is derived from platinic chloride, PtCl and the other from platinous chloride, PtCl2. The co-ordination number of the former is six and the latter, four. Thus, with ammonia and chlorine as the acidic radicle in the complex,... 

I. Platinum-ammines derived from platinous chloride—PtCl2. 

Complex salts of platinum ammines were also made with dimethylamine, diethylamine, pyridine, and diethylsulphine. 

Although H-NMR resonances can be detected from NH protons with 14N present in natural abundance (99.6%), they are often broad because of the quadrupolar relaxation of 14N (/ = 1). It is also necessary to work in H20 (as opposed to D20), since NH protons in platinum ammine and amine complexes usually exchange with deuterium within minutes. The exchange of NH protons with solvent is much faster for PtIV than for Ptn complexes at... 

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

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