Novel Dinuclear Redox‐isomeric Complexes with a Tetrapodal Pyridine‐based Ligand1. Issue 11 (30th July 2014)

• Record Type: Journal Article
• Authors: Bubnov, Michael P.; Skorodumova, Nina A.; Zolotukhin, Alexey A.; Arapova, Alla V.; Baranov, Evgenii V.; Stritt, Anika; Ünal, Alper; Grohmann, Andreas; Heinemann, Frank W.; Bogomyakov, Artem S.; Smirnova, Natal'a N.; Cherkasov, Vladimir K.; Abakumov, Gleb A.
• Is Part Of: Zeitschrift für anorganische und allgemeine Chemie. Volume 640:Issue 11(2014)
• Page Start: 2177
• Page End: 2182
• Publication Date: 2014-07-30
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry -- Periodicals; 540
• DOI: 10.1002/zaac.201400242
• Languages: English
• ISSNs: 0044-2313

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Tris‐<italic>o</italic>‐semiquinonato cobalt complexes react with a tetrapodal pyridine‐derived ligand to form dinuclear cobalt compounds of general formula (OMP)[Co<italic>Q</italic><sub>2</sub>]<sub>2</sub>, where OMP = 2, 2′‐(pyridine‐2, 6‐diyl)bis(<italic>N</italic><sup>1</sup>, <italic>N</italic><sup>1</sup>, <italic>N</italic><sup>3</sup>, <italic>N</italic><sup>3</sup>‐tetramethylpropane‐1, 3‐diamine), <italic>Q</italic> = mono‐ or dianion of 3, 6‐di‐<italic>tert</italic>‐butyl‐<italic>o</italic>‐benzoquinone (complex <bold>1</bold>) and it derivatives: 3, 6‐di‐<italic>tert</italic>‐butyl‐4, 5‐<italic>N</italic>, <italic>N</italic>′‐piperazino‐<italic>o</italic>‐benzoquinone (complex <bold>2</bold>), and 3, 6‐di‐<italic>tert</italic>‐butyl‐4‐Cl‐<italic>o</italic>‐benzoquinone (complex <bold>3</bold>). Single crystal X‐ray crystallography of <bold>1</bold> and <bold>3</bold> indicates two bis‐quinonato cobalt units bound by an OMP ligand, which acts as a bridge. Each central cobalt atom is chelated by one <italic>N</italic><sup>1</sup>, <italic>N</italic><sup>1</sup>, <italic>N</italic><sup>3</sup>, <italic>N</italic><sup>3</sup>‐tetramethylpropane‐1, 3‐diamine and two <italic>o</italic>‐quinonato fragments. The nitrogen atom of the pyridine ring is uncoordinated. All complexes were characterized by NIR‐IR and EPR spectroscopy, precise adiabatic vacuum calorimetry, and by variable‐temperature magnetic susceptibility measurements. All data indicate a reversible thermally driven redox‐isomeric (valence tautomeric) transformation in the solid state for all complexes.</p> </abstract>