F. Rochon, R. Melanson, A. Morneau
Aug 1, 1992
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Influential Citations
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Journal
Magnetic Resonance in Chemistry
Abstract
The hydrolysis reactions of complexes of the type Pt(L)X2 where L is ethylenediamine (en), N,N‐ dimethylenediamine (N,N‐Me2en), N,N‐dimethylenediamine (N,N′‐Me2en) and N,N,N′, N′‐tetramethylethylenediamine (Me4en) were studied. The halo ligands were removed by precipitation with AgNO3 and the pH of the resulting filtrate, which was about 2, was adjusted to 5.8 (pD = 6.2). The study of the products formed was carried out by multinuclear NMR spectroscopy. The 195Pt NMR spectra showed the presence of several hydrolysed products, especially with en. The hydroxo‐bridged dimer can be synthesized in a pure state with all the ligands except en. The results on the latter ligand contradict the published results on the synthesis of the en hydroxo‐bridged dimer whose biological properties were studied. When Pt(L)I2 is used as starting material a small quantity of chloro species was always observed, indicating that the reactant contained a small quantity of Pt(L)ICI. The crystal structure of the [Pt(N,N‐Me2en)(μ‐OH)]2(NO3)2 dimer was determined. The compound belongs to the P21/c space group, with a = 8.262(5), b = 10.960(8), c = 11.405(8), β = 121.07(5)°, Z = 2 and ρcalc = 2.720 mg m−3. The results showed that this is the trans isomer with an inversion centre between the two Pt atoms. There is a considerable strain inside the four‐membered ring, as shown by the reduced internal angles OPtO′ = 79.1(6)0 and PtOPt′ = 101.0(6)°.