Testing the Push-Pull Hypothesis: Lewis Acid Augmented N2 Activation at Iron

J Am Chem Soc. 2017 Apr 26;139(16):5952-5956. doi: 10.1021/jacs.7b01982. Epub 2017 Apr 17.

Abstract

We present a systematic investigation of the structural and electronic changes that occur in an Fe(0)-N2 unit (Fe(depe)2(N2); depe = 1,2-bis(diethylphosphino)ethane) upon the addition of exogenous Lewis acids. Addition of neutral boranes, alkali metal cations, and an Fe2+ complex increases the N-N bond activation (Δ νNN up to 172 cm-1), decreases the Fe(0)-N2 redox potential, polarizes the N-N bond, and enables -N protonation at uncommonly anodic potentials. These effects were rationalized using combined experimental and theoretical studies.

Publication types

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

MeSH terms

  • Boranes / chemistry*
  • Electrochemical Techniques
  • Electrons
  • Iron Compounds / chemistry*
  • Lewis Acids / chemical synthesis
  • Lewis Acids / chemistry*
  • Molecular Conformation
  • Nitrogen / chemistry*

Substances

  • Boranes
  • Iron Compounds
  • Lewis Acids
  • Nitrogen