Synthesis, crystal structure, and NMR investigation of methyl α,α-dimethyl acetate-substituted π-allylpalladium complexes

The dimeric, trifluoroacetate-bridged π-allylpalladium complex 6 and the cationic allyl complex 8 were prepared and characterized by NMR spectroscopy as well as crystal structure analyses. The carbonyl group of the carboxylic ester moiety does not form a chelate with the metal atom. The activation enthalpy of a π–σ–π conversion could be determined to be 14.6 kcal mol−1 based on the dynamic NMR spectroscopy of the allylpalladium complex 8.