Theoretical Study on The Adsorption of NO on Metal Macrocycles, Metal=Mn,Fe,Co,Ni,Cu,Zn

Abstract

We have studied the electronic structure and the adsorption of nitric oxide (NO) on various metal phthalocyanines (MPc, M = Mn, Fe, Co, Ni, Cu, Zn). By fully optimized geometries and electronic structure of various MPcs, we found that the 3d states of metals mainly contributed to ground-state electronic structure near the Fermi level of MPc and, to some degree, the p states of carbon inner ring. Those contribution of 3d states decreases as we move across the periodic table from Mn to Zn following the increase of d orbital occupancies. We also found that NO strongly bonds to the centre metal with end-on configuration and results in an opening of HOMO-LUMO energy gap in case of MnPc, FePc, and CoPc. While it shows a physisorption with other MPcs (Ni, Cu, and Zn) and results in an appearance of molecular electronic states at HOMO-LUMO gap.