Aseries of BPh4 - and other Pd-allyl salts of the form [Pd(η3-allyl)(N,N-chelate)](anion) (η3-allyl= CH2C(Me)CH2, 3, and PhCHCHCHPh, 4) have been prepared and studied via PGSE diffusion and other forms of NMR spectroscopy together with X-ray and DFT calculations. The diffusion data reveal that the BPh4 - salts show a very substantial amount of ion pairing in CD2Cl2 solution. Both the solution Overhauser studies and the X-ray results are consistent with a BPh4 - position that brings one or more phenyl groups very close to the N,N-chelate, and this would facilitate phenylation reactions. Variable-temperature and magnetization transfer NMR measurements reveal allyl and ligand dynamics that fall under the general heading of “apparent rotation”.DFTcalculations suggest that this isomerization process in 3 and 4 is solvent assisted and proceeds with Pd-Nbond breaking.
Ion Pairing and Allyl Dynamics in a Series of [Pd(η3-allyl)(N,Nchelate)]( anion) Salts. On the Influence of the BPh4 - Anion / A. Moreno, P.S. Pregosin, B. Fuentes, L.F. Veiros, A. Albinati, S. Rizzato. - In: ORGANOMETALLICS. - ISSN 0276-7333. - 28:22(2009), pp. 6489-6506. [10.1021/om900697e]
Ion Pairing and Allyl Dynamics in a Series of [Pd(η3-allyl)(N,Nchelate)]( anion) Salts. On the Influence of the BPh4 - Anion
A. AlbinatiPenultimo
;S. RizzatoUltimo
2009
Abstract
Aseries of BPh4 - and other Pd-allyl salts of the form [Pd(η3-allyl)(N,N-chelate)](anion) (η3-allyl= CH2C(Me)CH2, 3, and PhCHCHCHPh, 4) have been prepared and studied via PGSE diffusion and other forms of NMR spectroscopy together with X-ray and DFT calculations. The diffusion data reveal that the BPh4 - salts show a very substantial amount of ion pairing in CD2Cl2 solution. Both the solution Overhauser studies and the X-ray results are consistent with a BPh4 - position that brings one or more phenyl groups very close to the N,N-chelate, and this would facilitate phenylation reactions. Variable-temperature and magnetization transfer NMR measurements reveal allyl and ligand dynamics that fall under the general heading of “apparent rotation”.DFTcalculations suggest that this isomerization process in 3 and 4 is solvent assisted and proceeds with Pd-Nbond breaking.Pubblicazioni consigliate
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