88083-20-9Relevant articles and documents
PGSE NMR diffusion, overhauser, and DFT studies on the salts [Pd(η3-CH3CHCHCHPh)(dppe)](anion)
Schott, Daniele,Pregosin, Paul S.,Veiros, Luis F.,Calhorda, Maria Jose
, p. 5710 - 5717 (2008/10/09)
PGSE NMR diffusion, Overhauser and DFT studies on the salts [Pd(η3-CH3CHCHCHPh)-(dppe)](anion) (dppe = 1,2-bis(diphenylphosphino)ethane, anion = BF4-, CF 3SO3-, BArF-, PF6 -) are reported. In dichloromethane solution there is little or no ion pairing for the BArF derivative, whereas the other three anions show intermediate degrees of ion pairing. In chloroform solution the CF 3SO3- and BArF- salts show complete ion pairing. The 19F,1H HOESY studies reveal a selective approach of the CF3SO3- and PF6 - anions with respect to the allyl ligand. The approach brings the anion somewhat closer to the allyl phenyl ring than to the allyl methyl group. Further, the anion approaches the Pd center from the side of the two terminal allyl protons. The anions are not attracted to the allyl ligand but rather are choosing both an electronically (allyl phenyl vs allyl methyl) and sterically (terminal allyl protons vs central allyl proton) preferred pathway toward the P and metal atoms. This result is partially rationalized via DFT calculations.