Mechanically activated transformations in the coordination sphere of platinum complexes induced by impact grinding of solid K2PtX6 (X=Cl, Br) and K2PtCl4 salts

Mechanical treatment of solid K2PtX6 (X=Cl, Br) salts under air or argon leads to the formation of paramagnetic platinum(III) complexes via homolytic cleavage of PtX bonds. Lewis acid sites (LASs) were also detected on the surface of mechanically activated K2PtCl6 using a paramagnetic probe. The latter species can be attributed to coordinatively unsaturated platinum(IV) complexes formed as a result of heterolysis of PtCl bonds. Mechanical treatment of solid K2PtCl4, on the contrary, does not lead to homolytic PtCl bond cleavage. In this case only heterolysis of the PtCl bond takes place, leading to the formation of coordinatively unsaturated platinum(II) complexes.