Selective adsorption of metal-phthalocyanine on Au(111) surface with hydrogen atoms

Metal phthalocyanine (MPc, M = Mn, Fe) molecules grown on reconstructed Au(111) with and without hydrogen atoms at submonolayer coverage are investigated by low temperature scanning tunneling microscopy. It is found out that the attachment of H atoms to the central metal of the MnPc molecules leads to the change of the molecules' selective adsorption from fcc to hcp regions at low coverage. The two configurations of MnPc molecules on Au(111) are replaced by only one configuration of H-MnPc/Au(111). FePc molecules adsorb on fcc regions of Au(111) with two configurations, which are similar to that of MnPc. However, unlike H-MnPc, H-FePc molecules have two configurations on Au(111). Density function theory calculations show that the different configuration change by attachment of H atoms for MnPc and FePc molecules is due to the electronic structure change at the central metal atoms of the molecules. (C) 2013 AIP Publishing LLC.