Nickel, Platinum, and Palladium Complexes

NMR behavior down to -90°C where the single triplet resonance (Jpp = 3.0 Hz) became two unresolved multiplets. The low activation energy for the intramolecular rearrangement of the Ni and Ft complexes is in sharp contrast to the compound [(CF3)gCe](7r-C5H5)Rh which has been shown to contain a tetrahapto-coordinated (CF3)eCg ligand (65). 

Palladium(II) acetate has been found to be a catalyst for the dimerization of benzene to biphenyl in perchloric acid-acetic acid solutions 80). Kinetic studies suggested the formation of an intermediate complex between a benzene molecule and a Pd(II) ion, and the following reaction sequence was proposed  

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Ruthenium complex 33 has been prepared by thermolysis as shown in Scheme 1 for early transition metals [25]. However, this procedure is not applicable to nickel, platinum and palladium complexes because they undergo reductive elimination, rather than beta elimination. Complexes 31 and 32 have been prepared by sodium amalgam reduction of the corresponding a-complex 37, as shown in Scheme 6 [6,7,24]. 

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