Dipalladium Complexes with Bridging Monoalkyl or Monophenyl Silyl Ligands in the Solid State and in Solution

HexSiH3, PhSiH3, and PhSiClH2 reacted with
[Pd­(PCy3)2] to yield dipalladium complexes with
bridging silyl ligands: [{Pd­(PCy3)}2(μ-HSiXR)2] (1, R = Hex, X = H; 2, R = Ph,
X = H; 3, R = Ph, X = Cl). The X-ray crystallographic
results displayed a typical bis­(silyl)-bridged dinuclear structure
with an anti conformation of the substituents on the Si atom in the
solid state. Temperature-dependent NMR spectroscopic analyses of 1 and 2 revealed a dynamic syn–anti isomerization of the complex via exchange
of the bridging and nonbridging Si–H hydrogens in solution.
Complex 3 with bridging chloro­(phenyl)­silyl ligands did
not show such a dynamic behavior.