The Formazanate Ligand as an Electron Reservoir: Bis(Formazanate) Zinc Complexes Isolated in Three Redox States
Journal
Angewandte Chemie International Edition
Journal Volume
53
Journal Issue
16
Pages
4118-4122
Date Issued
2014
Author(s)
Chang, Mu-Chieh
Dann, Thomas
Day, David P.
Lutz, Martin
Wildgoose, Gregory G.
Otten, Edwin
Abstract
The synthesis of bis(formazanate) zinc complexes is described. These complexes have well-behaved redox-chemistry, with the ligands functioning as a reversible electron reservoir. This allows the synthesis of bis(formazanate) zinc compounds in three redox states in which the formazanate ligands are reduced to "metallaverdazyl" radicals. The stability of these ligand-based radicals is a result of the delocalization of the unpaired electron over four nitrogen atoms in the ligand backbone. The neutral, anionic, and dianionic compounds (L2 Zn(0/-1/-2)) were fully characterized by single-crystal X-ray crystallography, spectroscopic methods, and DFT calculations. In these complexes, the structural features of the formazanate ligands are very similar to well-known β-diketiminates, but the nitrogen-rich (NNCNN) backbone of formazanates opens the door to redox-chemistry that is otherwise not easily accessible.
SDGs
Type
journal article