Alkyl and hydrido complexes of platinum(IV) supported by the bis(8-quinolyl)methylsilyl ligand

The Pt(II) complex (NSiN)PtCl (2; NSiN = bis(8-quinolyl)methylsilyl) was prepared from reaction of (COD)PtCl2, Qn(2)SiHMe (1) and excess NEt3 in dichloromethane. The X-ray structure of 2 confirms a square-planar geometry about platinum and a highly distorted tetrahedral geometry at Si. A series of thermally stable (NSiN)Pt(IV) compounds including (NSiN)PtH2(X) [X = Cl (5), OTf (10)] and (NSiN)PtMe2(X) [X = 1 (6), OTf (7)] were also synthesized. Five-coordinate Pt(IV) complexes of the type [(NSiN)PtR2][B(C6F5)(4)] (X = Me (9), H (11)] were generated by treatment of the corresponding triflato derivatives with 1 equiv of Li(Et2O)(3)[B(C6F5)(4)] in dichloromethane. A crystal structure of 9 reveals a square-pyramidal structure with an empty coordination site trans to silicon. Initial reactivity studies have shown that complex 9 is thermally and chemically robust.