Valence tautomerism in cobalt complexes based on isopropyl- and cyclohexyl-substituted o-quinones

A series of novel dioxolene cobalt complexes with general formula (N-N)Co(3,6-diox)2 (where N-N = 2,2'- dipyridine (bpy) and 1,10-phenanthroline (phen), diox - mono-and dianionic forms of 3,6-di-isopropyl-o-ben-zoquinone (3,6-iPr-Q) and 3,6-di-cyclohexyl-o-benzoquinone (3,6-cHex-Q)) has been synthesized and charac-terized. The molecular structures of dipyridine adducts have been established by single crystal X-Ray structural analysis. Magnetic susceptibility measurements detect solid-state valence-tautomeric transformation occurring for complexes (phen)Co(3,6-iPr-SQ)(2) and (bpy)Co(3,6-cHex-SQ)(2). The phase transitions that accompany valence tautomeric transformation have been investigated by differential scanning calorimetry (DSC).

Automated summary

A series of novel dioxolene cobalt complexes with various ligands have been synthesized and characterized. The molecular structures of the complexes with dipyridine ligands have been determined by X-Ray structural analysis. Magnetic susceptibility measurements reveal solid-state valence-tautomeric transformation, and the associated phase transitions have been investigated by differential scanning calorimetry.