Adsorption energies of porphyrins on MgO(100): An experimental benchmark for dispersion-corrected density-functional theory

Wolfram, Alexander; Tariq, Quratulain; Fernández, Cynthia Carolina; Muth, Maximilian; Gurrath, Martin; Wechsler, Daniel; Franke, Martin; Williams, Federico J.; Steinrück, Hans‐Peter; Meyer, Bernd; Lytken, Ole

doi:10.1016/j.susc.2021.121979

Cited by 10 publications

(13 citation statements)

References 45 publications

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“…The overall trend is very similar to that found by Wolfram et al for the same three molecules on MgO(100) using temperature-programmed desorption and density functional theory calculations . Experimentally, they found the order of ZnTPP and CoTPP to be reversed, but, in line with our observations on TiO 2 (110), they also found MgTPP to bind significantly stronger (30–40 kJ/mol) than the other two molecules.…”

Section: Resultssupporting

confidence: 91%

“…Experimentally, they found the order of ZnTPP and CoTPP to be reversed, but, in line with our observations on TiO 2 (110), they also found MgTPP to bind significantly stronger (30–40 kJ/mol) than the other two molecules. It is important to note that these adsorption-energy differences are still small compared to the total adsorption energies of the whole molecules, which on MgO(100) were found to be 170–220 kJ/mol . Wolfram et al explain the adsorption-energy trends on MgO(100) in terms of oxophilicity, calculated by them as the adsorption energy of water molecules at the metal center and by Olsson et al as the adsorption energy of a methanol molecule.…”

Section: Resultsmentioning

confidence: 99%

“…Because desorption of the multilayers stops the reaction, the correct temperature to use is the multilayer desorption temperature. Importantly, all three molecules we have investigated (CoTPP, ZnTPP and MgTPP) have the same multilayer desorption temperature of 500 ± 10 K . Small differences in multilayer desorption temperatures will lead to preferential desorption of one species and thereby, especially for thicker multilayers, an enrichment of the other species in the remaining monolayer.…”

Section: Methodsmentioning

confidence: 99%

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Accurate Determination of Adsorption-Energy Differences of Metalloporphyrins on Rutile TiO₂(110) 1 × 1

et al. 2022

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Understanding the adsorption of organic molecules on surfaces is of essential importance for many applications. Adsorption energies are typically measured using temperature-programmed desorption. However, for large organic molecules, often only desorption of the multilayers is possible, while the bottom monolayer in direct contact to the surface cannot be desorbed without decomposition. Nevertheless, the adsorption energies of these directly adsorbed molecules are the ones of the most interest. We use a layerexchange process investigated with X-ray photoelectron spectroscopy to compare the relative adsorption energies of several metalated tetraphenylporphyrins on rutile TiO 2 (110) 1 × 1. We deposit a mixture of two different molecules, one on top of the other, and slowly anneal above their multilayer desorption temperature. During the slow heating, the molecules begin to diffuse between the layers and the molecules with the stronger interaction with the surface displace the weaker-interacting molecules from the surface and push them into the multilayer. The multilayers eventually desorb, leaving behind a monolayer of strongly interacting molecules. From the ratio of the two different porphyrin molecules in the residual monolayer and the desorbed multilayer, we can calculate the equilibrium constant of the layer-exchange process and thereby the difference in adsorption energy between the two different porphyrin molecules.

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Section: Resultssupporting

confidence: 91%

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

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Accurate Determination of Adsorption-Energy Differences of Metalloporphyrins on Rutile TiO₂(110) 1 × 1

et al. 2022

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“…This indicates that the molecules are mobile at RT or even below and that there are intermolecular forces stabilizing the assemblies. The apparent height of isolated molecules measured by STM at a bias voltage of 3.5 V yields (0.25 ± 0.04) nm which can be taken as proof that the molecules are flat ly- ing similar to findings of other porphyrins on oxide surfaces [21,[43][44][45].…”

Section: H-tcnpp On Rs-coo(100): Self-assemblysupporting

confidence: 74%

Adsorption, self-assembly and self-metalation of tetra-cyanophenyl porphyrins on semiconducting CoO(100) films

2022

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“…(3) which the parameter set of coordination-dependent C 6 coefficients is extended by additional values for atoms at higher coordination numbers 30,31 .…”

Section: Methodsmentioning

confidence: 99%

Resolution of intramolecular dipoles and push-back effect of individual molecules on a metal surface

Trishin¹,

Müller²,

Rolf³

et al. 2022

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Molecules consisting of a donor and an acceptor moiety can exhibit large intrinsic dipole moments. Upon deposition on a metal surface, the dipole may be effectively screened and the charge distribution altered due to hybridization with substrate electronic states. Here, we deposit Ethyl-Diaminodicyanoquinone molecules, which exhibit a large dipole moment in gas phase, on a Au(111) surface. Employing a combination of scanning tunneling microscopy and non-contact atomic force microscopy, we find that a significant dipole moment persists in the flat-lying molecules. Density-functional theory calculations reveal that the dipole moment is even increased on the metal substrate as compared to the gas phase. We also show that the local contact potential across the molecular islands is decreased by several tens of meV with respect to the bare metal. We explain this by the induced charge-density redistribution due to the adsorbed molecules, which confine the substrate's wavefunction at the interface. Our local measurements provide direct evidence of this so-called push-back or cushion effect at the scale of individual molecules.

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Adsorption energies of porphyrins on MgO(100): An experimental benchmark for dispersion-corrected density-functional theory

Cited by 10 publications

References 45 publications

Accurate Determination of Adsorption-Energy Differences of Metalloporphyrins on Rutile TiO₂(110) 1 × 1

Accurate Determination of Adsorption-Energy Differences of Metalloporphyrins on Rutile TiO₂(110) 1 × 1

Adsorption, self-assembly and self-metalation of tetra-cyanophenyl porphyrins on semiconducting CoO(100) films

Resolution of intramolecular dipoles and push-back effect of individual molecules on a metal surface

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Adsorption energies of porphyrins on MgO(100): An experimental benchmark for dispersion-corrected density-functional theory

Cited by 10 publications

References 45 publications

Accurate Determination of Adsorption-Energy Differences of Metalloporphyrins on Rutile TiO2(110) 1 × 1

Accurate Determination of Adsorption-Energy Differences of Metalloporphyrins on Rutile TiO2(110) 1 × 1

Adsorption, self-assembly and self-metalation of tetra-cyanophenyl porphyrins on semiconducting CoO(100) films

Resolution of intramolecular dipoles and push-back effect of individual molecules on a metal surface

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Accurate Determination of Adsorption-Energy Differences of Metalloporphyrins on Rutile TiO₂(110) 1 × 1

Accurate Determination of Adsorption-Energy Differences of Metalloporphyrins on Rutile TiO₂(110) 1 × 1