Changes of the Molecule-Substrate Interaction upon Metal Inclusion into a Porphyrin

Metal-dependent conformations: A change in the adaptation of tetraphenylporphyrins (TPPs) on Ag(111) was observed in the presence of a metal ion in the macrocycle. Upon annealing at T>575 K, 2H-TPP molecules increase the overlap of the phenyl ? orbitals with the substrate, thus reducing the distance. The presence of Co creates a strong bond between Co d and the Ag sp states, leaving the porphyrin macrocycle at a larger distance to the surface