Binding configuration, electronic structure, and magnetic properties of metal phthalocyanines on a Au(111) surface studied withab initiocalculations

Binding configurations, interface electronic structures, and magnetic properties of 3d transition-metal phthalocyanine (MPc, where M $=$ Mn, Fe, Co, Ni, Cu or Zn) molecular systems on a Au(111) substrate are systematically investigated with first-principles density functional theory calculations using the Perdew-Wang (PW91) exchange-correlation functional. We also calculate the corresponding properties of freestanding molecules and make comparisons between these two cases. It is found that MnPc, FePc, and CoPc have a stronger binding configuration than that of NiPc, CuPc, and ZnPc. For the magnetic properties of the MPc molecules, it is not affected after molecular adsorption, except for CoPc. In addition, for the adsorption properties of FePc on Au(111), we find that the low adsorption energy and small energy differences between different configurations allow the FePc molecules to diffuse easily on a Au(111) substrate at certain temperatures.