Nitrogen fixation revisited on iron(0) dinitrogen phosphine complexes

Inorg Chem. 2015 May 18;54(10):4768-76. doi: 10.1021/acs.inorgchem.5b00211. Epub 2015 May 6.

Abstract

A reinvestigation of the treatment of [Fe(N2)(PP)2] (PP = depe, dmpe) with acid revealed no ammonium formation. Instead, rapid protonation at the metal center to give hydride complexes was observed. Treatment of [Fe(N2)(dmpe)2] with methylating agents such as methyl triflate or methyl tosylate resulted in methylation of the metal center to afford [FeMe(N2)(dmpe)2](+). Treatment of [Fe(N2)(dmpe)2] with trimethylsilyl triflate, however, resulted in reaction at dinitrogen affording NH4(+) on subsequent treatment with acid. The side-on bound hydrazine complex [Fe(N2H4)(dmpe)2](2+) and bis(ammonia) complex [Fe(NH3)2(dmpe)2](2+) were identified by (15)N NMR spectroscopy as other species formed in the reaction mixture.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ammonia / chemistry
  • Benzenesulfonates / chemistry
  • Coordination Complexes / chemistry*
  • Hydrazines / chemistry
  • Iron / chemistry*
  • Magnetic Resonance Spectroscopy
  • Mesylates / chemistry
  • Nitrogen / chemistry*
  • Nitrogen Fixation
  • Phosphines / chemistry*
  • Protons*
  • Trimethylsilyl Compounds / chemistry

Substances

  • Benzenesulfonates
  • Coordination Complexes
  • Hydrazines
  • Mesylates
  • Phosphines
  • Protons
  • Trimethylsilyl Compounds
  • hydrazine
  • methyl triflate
  • methyl tosylate
  • Ammonia
  • Iron
  • Nitrogen