Electronic Properties of Magnetic Salophenes Adsorbed on Ag(111)

For two decades, the Kondo effect has been employed to investigate magnetic properties of single molecules, oligomers, and molecular networks. However, this approach limits the possibility of using external magnetic fields to control the alignment of the magnetic moments of molecules due to Kondo screening. In light of recent advancements in on-surface synthesis of magnetic nanoribbons and organometallic complexes on Au(111), a new substrate that does not screen the magnetic moment and yet still supports on-surface chemistry is needed. Here, we study the electronic properties of the adsorbed molecule 5,5′-dibromosalophenatocobalt(II), with emphasis on the search for a Kondo resonance. It is found that the Kondo resonance is absent if the molecule is adsorbed on a Ag(111) surface, in contrast to Au(111). DFT calculations indicate similarities in the electronic structure and magnetism of the molecule on both substrates. However, the spin-polarized orbitals are shifted by approximately 0.3 eV toward lower energies on the Ag(111) substrate compared to Au(111), and below the surface state of Ag(111). This points toward a strategy for choosing an appropriate substrate for other molecular-metal hybrid systems.