Magnetic behaviour of polyfluoroacridine-based organic molecular materials

The solid state magnetic properties of two new molecular organic materials based on polyfluoro- acridines functionalised with the 2,2,6,6-tetramethyl piperidine-1-oxyl radical (TEMPO) have been analyzed. After a first characterisation of the two materials by electron paramagnetic resonance and by X-ray diffraction, magnetisation measurements were performed from room temperature down to 2 K and the paramagnetic behaviour due to the unpaired spin on the radical TEMPO observed. Both compounds show some ferro-magnetic interactions down to 40 K, while at lower temperatures an antiferro-magnetic contribution switches on, possibly related to the reduction of intermolecular distances.