Synthesis and comparative X-ray diffraction study of first ruthenocene-based pincer palladium complexes, PdCl[{2,5-(But2PCH2)2C5H2}Ru(Cp′)] (Cp′ = C5H5 or C5Me5)

First ruthenocene-based palladium complexes PdCl[{2,5-((Bu2PCH2)-P-t)(2)C5H2} Ru(Cp')] (Cp' = C5H5 (4) or C5Me5 (5)) were synthesized. Comparative single-crystal X-ray diffraction study of complexes 4 and 5 showed that the deviations of the cyclopentadienyl rings in these complexes from being parallel are 2.6 and 10.1 degrees, respectively. In addition, the shift of the palladium atom relative to the plane of the metallated cyclopentadienyl ligand is 0.007 angstrom for 4 and 0.336 angstrom for 5. These differences in the structures of complexes 4 and 5 are due to close contacts between the pseudoequatorial tert-butyl groups at the phosphorus atoms and the unmetallated cyclopentadienyl ring.