Hybridized Kondo State Formed by πradical Assemblies

We study the spin state of the πradical assemblies, which are created through converting nonmagnetic terbium (2,3,7,8,12,13,17,18-octaethylporphyrinate) (2,3,7,8,12,13,17,18-octaethylporphyrindiate) (Tb(Hoep)(oep)) selectively either into [Tb(oep)2] or deethyl-[Tb(oep)2] radical molecule by removing the H atom and further ethyl group, with the injection of tunneling electrons using a scanning tunneling microscope. The Kondo resonance, formed by screening the radical spin by the conduction electron, shows the dip and peak shapes for [Tb(oep)2] or deethyl-[Tb(oep)2], respectively, due to the difference in the coupling between the two oep ligands. When these two types of molecules are created next to each other, the Kondo resonance appears as a mixture of the peak and dip at the interface of the two. This is interpreted as the result of the hybridization of the two different πradical orbitals, suggesting a possible control of the Kondo state by designing the molecular orbitals.