Magnetic Properties and Redox Isomerism for 4,4‘-Bis(semiquinone) Complexes of Copper

Polymeric [CuII(SQMe−SQMe)]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)CuII(CatMe−BQMe) and (PPh3)2CuI(SQMe−BQMe) show that the bis(quinone) ligand is capable of intramolecular modulation of charge distribution.