Dinickel(II) complexes: preparation and catalytic activity

Dalton Trans. 2012 Mar 28;41(12):3468-73. doi: 10.1039/c2dt11398h. Epub 2012 Feb 3.

Abstract

Ligands (L(a-c)) based on 2,7-bis(3,5-di-R-pyrazol-1-yl)-1,8-naphthyridine (a, R = H; b, R = CH(3); c, R = Ph) were prepared for the construction of a series of dinickel complexes. Treatment of L(x) with NiCl(2) in an anhydrous methanol/THF solution resulted in the formation of dinuclear complexes [(L(x))(μ-Cl)(2)Ni(2)Cl(2)(CH(3)OH)(2)] (3, x = a; 4, x = b; 5, x = c). These new complexes were characterized by elemental analysis, IR and UV-Vis spectroscopic techniques. The structures of complexes 3 and 4 were further confirmed by X-ray diffraction studies. Interestingly, crystals of 4 were obtained as a co-crystallization of 4 and the methanol substituted species [{(L(b))(μ-Cl)(2)Ni(2)Cl(CH(3)OH)(3)}Cl] (4'). These dinickel complexes have been tested in the catalytic homo-coupling of terminal alkynes with the use O(2) as the oxidant, showing excellent activities. A clear improvement on the catalytic activity of these complexes is observed as compared to the mono-nuclear species.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Catalysis
  • Crystallography, X-Ray
  • Ligands
  • Methanol / chemistry*
  • Models, Chemical
  • Molecular Structure
  • Nickel / chemistry*
  • Organometallic Compounds / chemical synthesis*
  • Spectrophotometry, Ultraviolet

Substances

  • Ligands
  • Organometallic Compounds
  • Nickel
  • Methanol