Synthesis and characterization of (π-allyl)palladium(II) complexes containing dialkylbiaryl phosphine ligands

• Published in: Polyhedron Vol. 114; pp. 101 - 109
• Main Authors: McGarry, Katherine R., McDaniel, Michael, Chan, Benny C., O’Connor, Abby R.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 16.08.2016
• Subjects: (π-Allyl) complexes; Metal–arene interactions; Pd(II) complexes; Phosphines; X-ray structure; Metal–arene interactions; Pd(II) complexes; X-ray structure; Phosphines; (π-Allyl) complexes
• ISSN: 0277-5387
• DOI: 10.1016/j.poly.2015.11.002

Neutral and cationic (π-allyl)Pd(II) complexes containing Buchwald-type dialkylbiaryl phosphines have been synthesized and structurally characterized. In the cationic complexes, coordination of the palladium center to the lower pendent ring is observed in solution and in the solid state; the hapticity is dependent on the substituents on the lower ring. [Display omitted] Neutral (π-allyl)palladium(II) halide complexes, which are air and moisture tolerant, containing dialkylbiaryl (alkyl=cyclohexyl or t-butyl) phosphine ligands, have been synthesized and characterized by 1H, 31P, 13C NMR spectroscopy, X-ray crystallography, and elemental analysis. Exposure of the halide complexes to sodium tetrakis(3,5-bis(trifluoromethyl)tetraphenylborate) (NaB(ArF)4) yields (π-allyl)palladium(II) cations, in which coordination of the pendent lower ring of the biphenyl moiety of the dialkylbiaryl phosphine ligand occurs. These cations have been characterized by 1H, 31P, 13C NMR spectroscopy, X-ray crystallography, and elemental analysis. The cationic complexes are not fluxional on the NMR timescale and a significant interaction exists between palladium and the arene group.