Preparation of stable alkyl complexes of Ni(I) and their one-electron oxidation to Ni(II) complex cations

J Am Chem Soc. 2004 Sep 1;126(34):10554-5. doi: 10.1021/ja047052z.

Abstract

The three-coordinate nickel(I) alkyl complexes (dtbpe)Ni(CH2CMe3) (2), (dtbpe)Ni(CH2SiMe3) (3), and (dtbpe)Ni(CH2CMe2Ph) (4) have been prepared by treatment of [(dtbpe)NiCl]2 with alkyllithium reagents. While thermally robust, they each undergo mild one-electron oxidation to give the corresponding Ni(II) complex cations [(dtbpe)Ni(CH2CMe3)+] (5), [(dtbpe)Ni(CH2SiMe3)+] (6), and [(dtbpe)Ni(CH2CMe2Ph)+] (7) as red-brown [PF6-] or [BArF4-] salts. In contrast to cationic amido and phosphido analogues that undergo alpha-deprotonation to afford imido and phosphinidene derivatives, deprotonation of 5-7 occurs at a gamma-CH3 group to give metallacyclobutane products (dtbpe)Ni(CH2CMe2CH2) (8), (dtbpe)Ni(CH2SiMe2CH2) (9), and (dtbpe)Ni(CH2CPhMeCH2) (10), not (dtbpe)Ni=CHR.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Cations, Divalent / chemistry
  • Cations, Monovalent / chemistry
  • Crystallography, X-Ray
  • Electron Spin Resonance Spectroscopy
  • Molecular Structure
  • Nickel / chemistry*
  • Organometallic Compounds / chemical synthesis
  • Organometallic Compounds / chemistry*
  • Oxidation-Reduction

Substances

  • Cations, Divalent
  • Cations, Monovalent
  • Organometallic Compounds
  • Nickel