Arylpalladium Complexes with a Silsesquioxanate Ligand. Preparation and Structures in the Solid State and in Solution

The reaction of the incompletely condensed silsesquioxane (c-C5H9)7Si7O9(OH)3 with [Pd(C6H3Me2-2,4)(I)(bpy)] produced a complex with a Pd−O bond, [Pd(C6H3Me2-2,4){(c-C5H9)7Si7O10(OH)2}(bpy)].
Palladium complexes having a silsesquioxanate ligand, [Pd(Ar){R7Si7O10(OH)2}(tmeda)] (Ar = C6H5,
C6F5, C6H3F2-2,4; R = c-C5H9, i-C4H9), were prepared by the reaction of the silsesquioxane R7Si7O9(OH)3 with arylpalladium iodo complexes, [Pd(Ar)(I)(tmeda)] (tmeda = N,N,N‘,N‘-tetramethylethylenediamine), in the presence of Ag2O. These complexes were characterized by multinuclear (1H, 13C{1H},
19F{1H}, and 29Si{1H}) NMR spectroscopy, and the structure of [Pd(C6F5){(c-C5H9)7Si7O10(OH)2}(tmeda)]
was determined by X-ray crystallography. Temperature-dependent 1H and 19F{1H} NMR spectra revealed
the dynamic behavior of the complexes on the NMR time scale.