Evidence for the formation of an intermediate complex in the direct metalation of tetra(4-bromophenyl)-porphyrin on the Cu(111) surface

A strong molecule-surface interaction between free-base-tetra(4-bromophenyl)-porphyrin and Cu(111) results in a distortion of both the molecule and the underlying copper surface in the vicinity of the molecule. This in turn leads to the formation of an intermediate complex due to bonding between the iminic nitrogens and surface copper atoms.