Mono‐ and Dinuclear Heteroleptic Cobalt Complexes with α‐Diimine and Polyarene Ligands. Issue 38 (4th August 2015)

• Record Type: Journal Article
• Authors: Wang, Xuting; Zhao, Yanxia; Gong, Shida; Liu, Bin; Li, Qian‐Shu; Su, Ji‐Hu; Wu, Biao; Yang, Xiao‐Juan
• Is Part Of: Chemistry. Volume 21:Issue 38(2015)
• Page Start: 13302
• Page End: 13310
• Publication Date: 2015-08-04
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201500983
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Reactions of the dimeric cobalt complex [(L<sup>−</sup>Co)<sub>2</sub>] (<bold>1</bold>, L=[(2, 6‐<italic>i</italic>Pr<sub>2</sub>C<sub>6</sub>H<sub>3</sub>)NC(Me)]<sub>2</sub>) with polyarenes afforded a series of mononuclear and dinuclear complexes: [LCo(η<sup>4</sup>‐anthracene)] (<bold>2</bold>), [LCo(μ‐η<sup>4</sup>:η<sup>4</sup>‐naphthalene)CoL] (<bold>3</bold>), and [LCo(μ‐η<sup>4</sup>:η<sup>4</sup>‐phenanthrene)CoL] (<bold>4</bold>). The pyrene complexes [{Na<sub>2</sub>(Et<sub>2</sub>O)<sub>2</sub>}{LCo(μ‐η<sup>3</sup>:η<sup>3</sup>‐pyrene)CoL}] (<bold>5</bold>) and [{Na<sub>2</sub>(Et<sub>2</sub>O)<sub>3</sub>}{LCo(η<sup>3</sup>‐pyrene)}] (<bold>6</bold>) were obtained by treating precursor <bold>1</bold> with pyrene followed by reduction with Na metal. These complexes contain three potential redox active centers: the cobalt metal and both α‐diimine and polyarene ligands. Through a combination of X‐ray crystallography, EPR spectroscopy, magnetic susceptibility measurement, and DFT computations, the electronic configurations of these complexes were studied. It was determined that complexes <bold>2</bold>–<bold>4</bold> have a high‐spin Co<sup>I</sup> center coupled with a radical α‐diimine ligand and a neutral polyarene ligand. Whereas, the ligand L in complexes <bold>5</bold> and <bold>6</bold> has been further reduced to the dianion, the cobalt remains in a formal (I) oxidation state, and the pyrene molecule is either neutral or monoanionic.</p> </abstract>