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)PtCl 2, Qn 2 SiHMe ( 1 ) and excess NEt 3 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)PtH 2 (X) [X = Cl ( 5 ), OTf ( 10 )] and (NSiN)PtMe 2 (X) [X = I ( 6 ), OTf ( 7 )] were also synthesized. Five-coordinate Pt(IV) complexes of the type [(NSiN)PtR 2 ][B(C 6 F 5 ) 4 ] (X = Me ( 9 ), H ( 11 )] were generated by treatment of the corresponding triflato derivatives with 1 equiv of Li(Et 2 O) 3 [B(C 6 F 5 ) 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.