Magnetic properties and electronic structure of new polyradicals based on nitronyl nitroxides

High-spin assemblies are of particular interest from the view point of ferromagnetic behaviour. The magnetic properties of a nitronyl nitroxide biradical based on a thiophen-fragment was investigated. In this polyradical the intra-molecular exchange interaction proofs to be stronger than the inter-molecular coupling within the solid. A detailed electron spin resonance analysis reveals the electronic structure of the molecular system. Therefore a conclusive picture of this new biradicals is presented, which may also be used as a ligand in the complexation with metal ions.