Nitric Oxide Adsorption Effects on Metal Phthalocyanines

Abstract

The adsorption of nitric oxide (NO) on various metal phthalocyanines (MPc, M = Mn, Fe, Co) has been studied using first-principles calculations based on density functional theory (DFT). In this study, we investigated the fully optimized geometries and electronic structure of MPc. We found that the electronic structures of metal atoms are essential in shaping the ground-state electronic structure near the Fermi level. These states are defined mostly by the d orbitals of the transition-metal atoms and, to some degree, by the states of nitrogen and carbon atoms of the inner rings. The numerical calculations showed that NO strongly chemisorbs to the metal atom with an end-on configuration and results in a change in geometric and electronic structures of MPc. The N-O bond lengths are slightly longer than that of the isolated NO molecule. The orbital energy levels are shifted with respect to the Fermi level. The HOMO-LUMO gap widens as compared to bare MPc. These changes are attributed to the hybridization of the pi* orbital of NO and the d orbitals of the transition metal. Specifically, the interaction between dpi and the pi* orbital is significant for MnPc-NO, while the hybridization of d(z(2)) and the pi* orbital plays an important role in CoPc-NO.

Atomic Imaging of the Irreversible Sensing Mechanism of NO2 Adsorption on Copper Phthalocyanine

“…This was checked by calculating the adsorption energy of NO on a more reactive MPc. For NO/CoPc, the DFT VASP plane wave calculation gives a binding energy of 1.57 eV, which agrees well with the binding energy of 1.55 eV calculated by Nguyen et al 47 for the same system, which also used the VASP plane wave code. It is noted that other computational methods give slightly higher binding energies; atomic-orbital DMol simulations of Lozzi et al showed a binding energy of 0.40 eV for NO 2 / CuPc.…”

Controlling orbital-selective Kondo effects in a single molecule through coordination chemistry

“…The coordination of CO and NO to metal ion of metal phthalocyanine, metal porphyrine, and their derivatives has been widely investigated from the viewpoints of coordination chemistry and biological chemistry. [28][29][30] A universal trend on the coordination geometry has been found that the CO molecule takes an upright configuration while the NO molecule favors the tilting configuration. This universal trend is true for the FePc adsorbed on Au(111).…”

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

“…The structures of MPc and NO-adsorbed MPc (MPc-NO) were fully optimized until the Hellmann-Feynman force exerted on an atom was less than 0.05eV/Å. The most stable structure of NO on MPc was found by optimizing several initial adsorption sites of NO related to MPc surface as discussed elsewhere [27], where NO molecule is placed on top of the metal atom of MPcs. The binding energy of NO with MPc is calculated from following expression: ∆E = EMPc+NO -(EMPc -ENO).…”