Platinum ethylenediamine complexes

Draw the structure of the platinum ethylenediamine complex [Pt(en)2]2+. Describe the coordination geometry, and identify any chelate rings. What are the coordination number and the oxidation number of the platinum ... 

Fig. 1.8. Structures of Pt complexes linked to intercalators. An acridine orange linked to a platinum—ethylenediamine complex and the proposed structure of a complex with Pt...

Deammoniation of this product at 130°C. gives platinum (II) amide. Similar reactions have been carried out with the ethylenediamine complex of platinum(II), and both the singly deprotonated product, [Pt(en)(en-H)]I, and the doubly deprotonated product, [Pt(en-H)2], were isolated as solid products and characterized (60). Later work showed that under proper conditions a white solid could be obtained which behaved as K[Pt(en-H)(en-2H)] (57). Each of these deprotonated species behaves as a strong base in aqueous solution, and the original material, [Pt(en)2] ", is regenerated. 

Inversions.—Currently there is considerable interest in comparing rates of inversion at nitrogen with rates of hydrogen exchange for cobalt(m) and for platinum(ii) complexes of ethylenediamine derivatives. Previous work has suggested that, whereas in cobalt(iii) systems rates of hydrogen exchange... 

The dimethylplatinum(ll) complex with a bidentate iV,iV,iV -trimethyl-A -(2-picolyl)ethylenediamine ligand undergoes methylation by Mel and protonation by several protic acids to produce cationic trimethylplatinum(iv) complex 1018 and methylplatinum(ll) complex 1019, respectively (Scheme 129). The protonation involves an intermediate cationic hydrido(dimethyl)platinum(lv) complex 1020. Scrambling of hydrogen atoms between hydride and methyl ligands during the reaction indicates an intermediate complex with methane as a ligand. 

A dimethylplatinum(ii) complex having monoimine of ethylenediamine with 9-phenanthraldehyde undergoes oxidative addition of Mel to afford dimethyl(iodo)platinum(iv) complex with terdentate C,jV,A-ligand. Complex 1029 with a six-membered cyclometallated imine ring and its isomer with a five-membered ring are obtained as a mixture (Equation (190)). ... 

CaH1gCl3Ns02Pt 3 H2O, trans-Nitrochloroamminediethylenetriamine-platinum(IV) chloride trihydrate, 45B, 1014 Ci,Hi 6Cli,Ni,03Re2 r Oxorhenium(V) ethylenediamine complex, 38B, 812 CftHigCluNftPt, cis-Dichlorobis(ethylenediamine)platinum(IV) chloride, 35B, 587... 

Kinetic parameters for the reactions of ra j-[Pt(NH3)4(OH)Cl] + and of tra r-[Pt(en)2(OH)Cl] with chloride ion have been obtained as a by-product of an investigation of the oxidative addition of chlorine to platinum(ii) complexes. For the bis-ethylenediamine complex an activation enthalpy of only 1 kcal mol is suggested the activation entropy is —34 cal deg mol. There has been a parallel study of the analogous bromo-system. ... 

Balthis and Bailar6 obtained tris (ethylenediamine) chromium-(III) complexes by the oxidation of chromium(II) solutions, using a procedure somewhat similar to that used for the synthesis of cobalt (III) com plexes. Mori7 described the preparation of hexaamminechromium(III) salts from the oxidation of chromium (II) salts in the presence of ammonia. The results obtained in both syntheses have been erratic.8,9 Berman noted that the foregoing syntheses are rendered dependable by the use of a catalyst of activated platinum on asbestos. Schaeffer,100 in a subsequent study, independently used colloidal platinum as a catalyst but reported some difficulty in separating it from the product.106 The procedures recommended and described here are based on the use of platinized asbestos as the catalyst. 

A series of ruthenium compounds has been obtained by replacing ammonia by ethylenediamine in the complex. These bring ruthenium completely into line with the other metals of the platinum group as far as co-ordination number is concerned. 

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