Rich redox-activity and solvatochromism in a family of heteroleptic cobalt complexes

Abstract

The combination of redox-active metals with redox-active ligands can lead to interesting charge transfer behaviours, including valence tautomerism and solvatochromism. With the aim of investigating a relatively underexplored redox-active metal/redox-active ligand combination, complexes [CoII(acac)2(X-BIAN)] (acac- = acetylacetonate; X-BIAN = bis(4-X-phenyl)iminoacenaphthene; 1: X = -CF3, 2: X = -Cl, 3: X = -H, 4: X = -Me) and [CoIII(acac)2(Me-BIAN)]+ (5+) have been synthesised and characterised. At all temperatures investigated, and in both the solid and solution state, complexes 1-4 exist in a CoII-BIAN0 charge distribution, while 5+ adopts a CoIII-BIAN0 charge distribution. In the case of ..