Spin conduction in nitroxide molecules

Spin conduction by a molecule-containing nitroxide radicals linked via a phenylene coupling unit was estimated by calculating the transmission of electrons in the molecule when sandwiched between two semi-infinite periodic gold crystals. Nitroxides linked via a m-phenylene coupling unit showed a large splitting in the energy of the transmission peaks of α- and β-spins, whereas this energy splitting was smaller for molecules with extended π-conjugation, such as nitroxides linked via a p-phenylene coupling unit. The energy splitting of transmission is influenced by spin polarization and constructive/destructive interference of radicals through the phenylene coupling unit.