Issue 5, 2019

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−1, −23.8 cal mol−1 K−1, 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.

Graphical abstract: Reversible homolytic activation of water via metal–ligand cooperativity in a T-shaped Ni(ii) complex

Supplementary files

Article information

Article type
Edge Article
Submitted
20 Aug 2018
Accepted
05 Nov 2018
First published
06 Nov 2018
This article is Open Access

All publication charges for this article have been paid for by the Royal Society of Chemistry
Creative Commons BY-NC license

Chem. Sci., 2019,10, 1360-1367

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, 10, 1360 DOI: 10.1039/C8SC03719A

This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. You can use material from this article in other publications, without requesting further permission from the RSC, provided that the correct acknowledgement is given and it is not used for commercial purposes.

To request permission to reproduce material from this article in a commercial publication, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party commercial publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements