Jump to main content
Jump to site search


Reversible Homolytic Activation of Water via Metal-Ligand Cooperativity in a T-Shaped Ni(II) Complex

Abstract

A T-shaped Ni(II) complex [Tol,PhDHPy]Ni has been prepared and characterized. EPR spectra and DFT calculations of this complex suggest that the electronic structure is best described as a high-spin Ni(II) center antiferromagnetically coupled with a ligand-based radical. This complex reacts with water at room temperature to generate the dimeric complex [Tol,PhDHPy]Ni(μ-OH)Ni[Tol,PhDHPyH] which has been thoroughly characterized by SXRD, NMR, IR and deuterium-labeling experiments. Addition of simple ligands such as phosphines or pyridine displaces water and demonstrates the reversibility of water activation in this system. The water activation step has been examined by kinetic studies and DFT calculations which suggest an unusual homolytic reaction via a bimetallic mechanism. The ΔH‡, ΔS‡ and KIE (kH/kD) of the reaction are 5.5 kcal/mol, −23.8 cal/(molK), and 2.4(1), respectively. In addition to the reversibility of water addition, this system is capable of activating water towards net O-atom transfer to substrates such as aromatic C-H bonds and phosphines. This reactivity is facilitated by the ability of the dihydrazonopyrrole ligand to accept H-atoms and illustrates the utility of metal ligand cooperation in activating O-H bonds with high bond dissociation energies.

Back to tab navigation

Supplementary files

Publication details

The article was received on 20 Aug 2018, accepted on 05 Nov 2018 and first published on 06 Nov 2018


Article type: Edge Article
DOI: 10.1039/C8SC03719A
Citation: Chem. Sci., 2019, Accepted Manuscript
  • Open access: Creative Commons BY-NC license
  •   Request permissions

    Reversible Homolytic Activation of Water via Metal-Ligand Cooperativity in a T-Shaped Ni(II) Complex

    M. Chang, K. A. Jesse, A. S. Filatov and J. S. Anderson, Chem. Sci., 2019, Accepted Manuscript , DOI: 10.1039/C8SC03719A

    This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. Material from this article can be used in other publications provided that the correct acknowledgement is given with the reproduced material and it is not used for commercial purposes.

    Reproduced material should be attributed as follows:

    • For reproduction of material from NJC:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the Centre National de la Recherche Scientifique (CNRS) and the RSC.
    • For reproduction of material from PCCP:
      [Original citation] - Published by the PCCP Owner Societies.
    • For reproduction of material from PPS:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the European Society for Photobiology, the European Photochemistry Association, and RSC.
    • For reproduction of material from all other RSC journals:
      [Original citation] - Published by The Royal Society of Chemistry.

    Information about reproducing material from RSC articles with different licences is available on our Permission Requests page.

Search articles by author

Spotlight

Advertisements