Spin-density distribution in the new molecular magnet p-O2N·C6F4·CNSSN

Knowledge of the spin-density distribution in the dithiadiazolyl radical ring (DTDA) constitutes a major step towards the understanding of the magnetic and electronic properties of the rich magnetism of DTDA derivatives. The O2N·C6F4CNSSN radical was chosen as the most favourable CNSSN derivative to study the spin distribution in this kind of free radicals by polarised-neutron diffraction. Spin-density maps obtained for the O2N C6F4CNSSN· radical show that almost all the spin density is localised on the sulphur and nitrogen atoms of the CNSSN· ring. A small negative spin density on the carbon atom of the CNSSN· ring and a negligible spin density over the rest of the radical are observed, in good agreement with ab initio calculations