Magnetic properties and redox isomerism for 4,4'-bis(semiquinone) complexes of copper

Polymeric [Cu-II(SQ(Me)-SQ(Me))](n) has been prepared with a bridging 4,4'-bis(semiquinone) ligand. Temperature-dependent magnetic properties result from ferromagnetic and antiferromagnetic coupling interactions involving the metal and the diradical ligands. Monomeric (bpy)Cu-II(Cat(Me)-BQ(Me)) and (PPh3)(2)Cu-I(SQ(Me)-BQ(Me)) show that the bis(quinone) ligand is capable of intramolecular modulation of charge distribution. [GRAPHICS]