Diplatinum complexes: Chemoselective reactions of the μ-orthometalated, metal–metal bonded complex [Pt2(μ-o-C6H4PPh2)(μ-PPh2)(PPh3)2] with acids. Crystal structures of [Pt2Cl(μ-PPh2)(PPh3)3], [Pt2I(μ-PPh2)(PPh3)3], [Pt2(μ-H)(μ-PPh2)I2(PPh3)2] and cis,cis-

In order to investigate further the chemoselectivity of reactions involving the μ-orthometalated, metal–metal bonded dinuclear Pt(I) complex [Pt2(μ-o-C6H4PPh2)(μ-PPh2)(PPh3)2](Pt–Pt) (1), it was reacted with HCl and HI using various stoichiometries. The first step was the breaking of the metal–carbon bond and the formation of C–H and Pt–X bonds. When a 1:1 ratio was used, the complexes [Pt2X(μ-PPh2)(PPh3)3](Pt–Pt) (2, X = Cl; 3, X = I) have been obtained but the use of a 2:1 ratio resulted instead in the formation of the complexes [Pt2(μ-H)(μ-PPh2)X2(PPh3)2](Pt–Pt) (4, X = Cl; 6, X = I). The latter transformed into [Pt2(μ-X)(μ-PPh2)X2(PPh3)2] (5, X = Cl; 7, X = I) in the presence of an additional equivalent of HX. The cis,cis- and cis,trans-isomers of 7 were also obtained by oxidation of 3 with one equivalent of iodine. Whereas compounds 4, cis,cis-5, and cis,trans-7 have been characterized in solution, the complexes 2·1/2C7H8, 3, 6 and cis,cis-7 have been isolated and structurally characterized by X-ray diffraction.

Protonation reactions involving the μ-orthometalated, metal–metal bonded dinuclear Pt(I) complex [Pt2(μ-o-C6H4PPh2)(μ-PPh2)(PPh3)2](Pt–Pt) have been investigated to examine their chemoselectivity. Reactions with HCl and HI using various stoichiometries have led to dinuclear Pt(I) and Pt(II) complexes, the first step being the breaking of the metal–carbon bond and the formation of C–H and Pt–halide bonds.Figure optionsDownload as PowerPoint slide