PGSE NMR Diffusion, Overhauser, and DFT Studies on the Salts [Pd(3-CH3CHCHCHPh)(dppe)](anion)
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- 作者：Daniele Schott ; Paul S. Pregosin ; Luis F. Veiros ; and Maria José ; Calhorda
- 刊名：Organometallics
- 出版年：2005
- 出版时间：November 7, 2005
- 年：2005
- 卷：24
- 期：23
- 页码：5710 - 5717
- 全文大小：208K
- 年卷期：v.24,no.23(November 7, 2005)
- ISSN：1520-6041
文摘
PGSE NMR diffusion, Overhauser and DFT studies on the salts [Pd(
3-CH3CHCHCHPh)(dppe)](anion) (dppe = 1,2-bis(diphenylphosphino)ethane, anion = BF4-, CF3SO3-, BArF-,PF6-) are reported. In dichloromethane solution there is little or no ion pairing for the BArFderivative, whereas the other three anions show intermediate degrees of ion pairing. Inchloroform solution the CF3SO3- and BArF- salts show complete ion pairing. The 19F,1HHOESY studies reveal a selective approach of the CF3SO3- and PF6- anions with respect tothe allyl ligand. The approach brings the anion somewhat closer to the allyl phenyl ringthan to the allyl methyl group. Further, the anion approaches the Pd center from the sideof the two terminal allyl protons. The anions are not attracted to the allyl ligand but ratherare choosing both an electronically (allyl phenyl vs allyl methyl) and sterically (terminalallyl protons vs central allyl proton) preferred pathway toward the P and metal atoms. Thisresult is partially rationalized via DFT calculations.
3-CH3CHCHCHPh)(dppe)](anion) (dppe = 1,2-bis(diphenylphosphino)ethane, anion = BF4-, CF3SO3-, BArF-,PF6-) are reported. In dichloromethane solution there is little or no ion pairing for the BArFderivative, whereas the other three anions show intermediate degrees of ion pairing. Inchloroform solution the CF3SO3- and BArF- salts show complete ion pairing. The 19F,1HHOESY studies reveal a selective approach of the CF3SO3- and PF6- anions with respect tothe allyl ligand. The approach brings the anion somewhat closer to the allyl phenyl ringthan to the allyl methyl group. Further, the anion approaches the Pd center from the sideof the two terminal allyl protons. The anions are not attracted to the allyl ligand but ratherare choosing both an electronically (allyl phenyl vs allyl methyl) and sterically (terminalallyl protons vs central allyl proton) preferred pathway toward the P and metal atoms. Thisresult is partially rationalized via DFT calculations.