Identification of the electronic states of manganese phthalocyanine close to the Fermi level

The electronic properties of two metal phthalocyanines, CuPc and MnPc, have been investigated by a combined experimental and theoretical approach. We demonstrate that the highest occupied molecular orbital of MnPc has significant metal 3d character, which is in contrast to CuPc where this state is of pure ligand π nature. This difference also explains the substantial variation in the ionization potential on going from CuPc to MnPc. Moreover, our results allow to identify the 1 e g symmetry of the Mn 3d state near the Fermi level, and they provide insight into the magnetic anisotropy of the two phthalocyanines.