279683-82-8Relevant articles and documents
Synthesis, characterization and X-ray structural determination of palladium(0)-olefin complexes containing pyridin-thioethers as ancillary ligands. Equilibria and rates of olefin and ligand exchange
Canovese, Luciano,Visentin, Fabiano,Chessa, Gavino,Uguagliati, Paolo,Dolmella, Alessandro
, p. 1 - 15 (2007/10/03)
The synthesis of Pd(0)-olefin complexes with pyridin-thioether ligands R′N-SR is reported. X-ray structure determinations of selected species are described. The dynamic behavior was studied by variable-temperature 1H-NMR spectrometry. Equilibrium constants for olefin and chelate ligand exchange were determined by UV-vis spectrophotometry in chloroform at 25°C. The following metal-olefin stability order was observed: tetramethylethylenetetracarboxylate (tmetc)≈naphthoquinone (nq)a similar extent, as found in similar Pd(II) complexes. When the entering olefin is tmetc, the approach to equilibrium is slow so that both second-order rate constants k2 and k-2 could be determined along with their activation parameters for the reversible reaction of [Pd(η2-nq)(HN-SiPr)] with tmetc. The results indicate an associative mechanism to be operative in these olefin exchange processes.