Complexes of platinum(II) with cis- and trans-1,2-bis(dimethylarsino) ethylene
1968; Elsevier BV; Volume: 2; Linguagem: Inglês
10.1016/s0020-1693(00)87065-6
ISSN1873-3255
AutoresM.A. Bennett, Gordon J. Erskine, JAKUB WILD,
Tópico(s)Photochemistry and Electron Transfer Studies
Resumocis-1,2-Dichloroethylene reacts with sodium dimethylarsenide to give a colourless oil containing the trans-and cis-isomers of 1,2-bis(dimethylarsino) ethylene (edas) in a ratio of about 10 to 1, as indicated by proton nmr measurements. The infrared spectrum and an approximate determination of the dipole moment support this conclusion. The oil reacts with potassium tetrachloroplatinate(II) to give an insoluble complex PtCl2(edas) and a water-soluble complex [Pt2(edas)4]Cl4.3H2O, which readily loses two molecules of ligand forming the insoluble complex. Derivatives of formula [Pt2(edas)4]X4 (X = PF6−, ClO4−, 12PtCl62− can also be isolated. The hexafluorophosphate and perchlorate derivatives behave as 4:1 electrolytes in ca. 10−3M nitromethane solution, while the chloride shows behaviour intermediate between that of a 1:1 and 2:1 electrolyte. The infrared spectra suggest that these complexes contain the trans-olefinic ditertiary arsine, and structures are suggested in which this ligand bridges two platinum atoms. Ultraviolet irradiation of solutions of the complex Pt2Cl4(trans-edas)4 yields an isomeric, water-soluble complex which is formulated as [Pt(cis-edas)2]Cl2 on the basis of its infrared spectrum. Derivatives of formula [Pt(cis-edas)2]2+X2 (X = PF6−, ClO4−, 12PtCl62−) can also be isolated; these, and the dichloride, behave as 2:1 electrolytes in ca. 10−3M nitromethane solution. These complexes are believed to contain two molecules of cis-1,2-bis(dimethylarsino)ethylene acting as a bidentate chelate ligand. The mechanisms for the observed isomerizations are briefly discussed.
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