The monoanionic π-radical redox state of α-iminoketones in bis(ligand)metal complexes of nickel and cobalt

Connie C. Lu, Eckhard Bill, Thomas Weyhermüller, Eberhard Bothe, Karl Wieghardt

Research output: Contribution to journalArticlepeer-review

40 Scopus citations

Abstract

The electronic structures of nickel and cobalt centers coordinated by two α-iminoketone ligands have been elucidated using density functional theory calculations and a host of physical methods such as X-ray crystallography, cyclic voltammetry, UV-vis spectroscopy, electron paramagnetic resonance spectroscopy, and magnetic susceptibility measurements. In principle, α-iminoketone ligands can exist in three oxidation levels: the closed-shell neutral form (L)0, the closed-shell dianion (L red)2-, and the open-shell monoanion (L )-. Herein, the monoanionic π-radical form (L)- of α-iminoketones is characterized in the compounds [(L)2Ni] (1) and [(L) 2Co] (3), where (L)- is the one-electron-reduced form of the neutral ligand (t-Bu)N=CH-C(Ph)=O. The metal centers in 1 and 3 are divalent, high-spin, and coupled antiferromagnetically to two ligand π radicals. These bis(ligand)metal complexes can be chemically oxidized by two electrons to give the dications [trans-(L)2Ni(CH 3CN)2](PF6)2 (2) and [trans-(L) 2Co(CH3-CN)2](PF6)2 (4), wherein the ligands are in the neutral form.

Original languageEnglish (US)
Pages (from-to)7880-7889
Number of pages10
JournalInorganic Chemistry
Volume46
Issue number19
DOIs
StatePublished - Sep 17 2007

Fingerprint

Dive into the research topics of 'The monoanionic π-radical redox state of α-iminoketones in bis(ligand)metal complexes of nickel and cobalt'. Together they form a unique fingerprint.

Cite this