title: The formazanate ligand as an electron reservoir: bis(formazanate) zinc complexes isolated in three redox states.
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.
authors.affiliation: Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen (The Netherlands).
authors.forename: Mu-Chieh
authors.initials: MC
authors.lastname: Chang
authors.forename: Thomas
authors.initials: T
authors.lastname: Dann
authors.forename: David P
authors.initials: DP
authors.lastname: Day
authors.forename: Martin
authors.initials: M
authors.lastname: Lutz
authors.forename: Gregory G
authors.initials: GG
authors.lastname: Wildgoose
authors.forename: Edwin
authors.initials: E
authors.lastname: Otten
mesh_terms: D005562:Formazans / Q000138:chemical synthesis* / Q000378:metabolism; D008024:Ligands; D008958:Models, Molecular; D015394:Molecular Structure; D010084:Oxidation-Reduction; D015032:Zinc / Q000737:chemistry*
chemical_list: D005562:Formazans; D008024:Ligands; D015032:Zinc
keywords: N ligands; formazanate; radical ligands; redox chemistry; zinc