Co and CoPc Molecular Kondo Box on Gold Surface

We demonstrate a class of Co and CoPc molecular Kondo boxes on the Au(111) surface through scanning tunneling microscopy experiments and first-principles calculations. The π-electron states of the CoPc molecule hybridize with the conduction electron states of the Au(111) substrate, imparting itinerantlike electron characteristics. Because of the high symmetry matching between the d_{π} orbitals of Co adatoms and the π orbitals of CoPc, the large orbital overlap predominates the formation of a Kondo singlet within the molecular complexes that prevail over the competition from the metal substrate, enabling them effectively as the molecular Kondo boxes. Furthermore, increasing the number of Co adatoms and modulating the overall symmetry of the molecular Kondo box can effectively tune the Kondo temperature T_{K}.