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Presel F, Kern CS, Boné TG, Schwarz F, Puschnig P, Ramsey MG, Sterrer M. Charge and adsorption height dependence of the self-metalation of porphyrins on ultrathin MgO(001) films. Phys Chem Chem Phys 2022; 24:28540-28547. [PMID: 36411984 PMCID: PMC9710497 DOI: 10.1039/d2cp04688a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 11/16/2022] [Indexed: 12/07/2023]
Abstract
We have experimentally determined the adsorption structure, charge state, and metalation state of porphin, the fundamental building block of porphyrins, on ultrathin Ag(001)-supported MgO(001) films by scanning tunneling microscopy and photoemission spectroscopy, supported by calculations based on density functional theory. By tuning the substrate work function to values below and above the critical work function for charging, we succeeded in the preparation of 2H-P monolayers which contain negatively charged and uncharged molecules. It is shown that the porphin molecules self-metalate at room temperature, forming the corresponding Mg-porphin, irrespective of their charge state. This is in contrast to self-metalation of tetraphenyl porphyrin (TPP), which occurs on planar MgO(001) only if the molecules are negatively charged. The different reactivity is explained by the reduced molecule-substrate distance of the planar porphin molecule compared to the bulkier TPP. The results of this study shed light on the mechanism of porphyrin self-metalation on oxides and highlight the role of the adsorption geometry on the chemical reactivity.
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Affiliation(s)
- Francesco Presel
- Institute of Physics, University of Graz, NAWI Graz, Universitätsplatz 5, A-8010 Graz, Austria.
| | - Christian S Kern
- Institute of Physics, University of Graz, NAWI Graz, Universitätsplatz 5, A-8010 Graz, Austria.
| | - Thomas G Boné
- Institute of Physics, University of Graz, NAWI Graz, Universitätsplatz 5, A-8010 Graz, Austria.
| | - Florian Schwarz
- Institute of Physics, University of Graz, NAWI Graz, Universitätsplatz 5, A-8010 Graz, Austria.
| | - Peter Puschnig
- Institute of Physics, University of Graz, NAWI Graz, Universitätsplatz 5, A-8010 Graz, Austria.
| | - Michael G Ramsey
- Institute of Physics, University of Graz, NAWI Graz, Universitätsplatz 5, A-8010 Graz, Austria.
| | - Martin Sterrer
- Institute of Physics, University of Graz, NAWI Graz, Universitätsplatz 5, A-8010 Graz, Austria.
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2
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Schio L, Forrer D, Casarin M, Goldoni A, Rogero C, Vittadini A, Floreano L. On surface chemical reactions of free-base and titanyl porphyrins with r-TiO 2(110): a unified picture. Phys Chem Chem Phys 2022; 24:12719-12744. [PMID: 35583960 DOI: 10.1039/d2cp01073a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this Perspective we present a comprehensive study of the multiple reaction products of metal-free porphyrins (2H-Ps) in contact with the rutile TiO2(110) surface. In the absence of peripheral functionalization with specific linkers, the porphyrin adsorption is driven by the coordination of the two pyrrolic nitrogen atoms of the macrocycle to two consecutive oxygen atoms of the protruding Obr rows via hydrogen bonding. This chemical interaction favours the iminic nitrogen uptake of hydrogen from near surface layers at room temperature, thus yielding a stable acidic porphyrin (4H-P). In addition, a mild annealing (∼100 °C) triggers the incorporation of a Ti atom in the porphyrin macrocycle (self-metalation). We recently demonstrated that such a low temperature reaction is driven by a Lewis base iminic attack, which lowers the energy barriers for the outdiffusion of Ti interstitial atoms (Tiint) [Kremer et al., Appl. Surf. Sci., 2021, 564, 150403]. In the monolayer (ML) range, the porphyrin adsorption site, corresponding to a TiO-TPP configuration, is extremely stable and tetraphenyl-porphyrins (TPPs) may even undergo conformational distortion (flattening) by partial cyclo-dehydrogenation, while remaining anchored to the O rows up to 450 °C [Lovat et al., Nanoscale, 2017, 9, 11694]. Here we show that, upon self-metalation, isolated molecules at low coverage may jump atop the rows of five-fold coordinated Ti atoms (Ti5f). This configuration is associated with the formation of a new coordination complex, Ti-O-Ti5f, as determined by comparison with the deposition of pristine titanyl-porphyrin (TiO-TPP) molecules. The newly established Ti-O-Ti5f anchoring configuration is found to be stable also beyond the TPP flattening reaction. The anchoring of TiO-TPP to the Ti5f rows is, however, susceptible to the cross-talk between phenyls of adjacent molecules, which ultimately drives the TiO-TPP temperature evolution in the ML range along the same pathway followed by 2H-TPP.
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Affiliation(s)
- Luca Schio
- CNR-IOM, Laboratorio TASC, Basovizza S.S. 14, Km 163.5, I-34149 Trieste, Italy.
| | - Daniel Forrer
- CNR-ICMATE and INSTM, via Marzolo 1, I-35131 Padova, Italy.
| | - Maurizio Casarin
- CNR-ICMATE and INSTM, via Marzolo 1, I-35131 Padova, Italy. .,Dipartimento di Scienze Chimiche, Università di Padova, via Marzolo 1, I-35131 Padova, Italy
| | - Andrea Goldoni
- Elettra-Sincrotrone Trieste S.C.p.A., Basovizza SS-14, Km 163.5, 34149 Trieste, Italy
| | - Celia Rogero
- Materials Physics Center MPC, Centro de Física de Materiales (CSIC-UPV/EHU) and Donostia International Physics Center (DIPC), E-20018 San Sebastian, Spain
| | | | - Luca Floreano
- CNR-IOM, Laboratorio TASC, Basovizza S.S. 14, Km 163.5, I-34149 Trieste, Italy.
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3
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Egger L, Hollerer M, Kern CS, Herrmann H, Hurdax P, Haags A, Yang X, Gottwald A, Richter M, Soubatch S, Tautz FS, Koller G, Puschnig P, Ramsey MG, Sterrer M. Ladungsunterstützte Selbstmetallierung von Porphyrinen auf Oxidoberflächen. ANGEWANDTE CHEMIE (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 133:5138-5142. [PMID: 38505778 PMCID: PMC10947009 DOI: 10.1002/ange.202015187] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Indexed: 03/21/2024]
Abstract
AbstractDas Interesse an Metallierungs‐ und Selbstmetallierungsreaktionen auf Oxidoberflächen ist in jüngster Zeit ständig gewachsen. Der Mechanismus der Selbstmetallierungsreaktion ist jedoch nicht vollständig geklärt. Hier zeigen wir mithilfe von Rastertunnelmikroskopie, Photoemissions‐Spektroskopie und Dichtefunktionaltheorie‐Rechnungen, dass die Selbstmetallierung von 2H‐Tetraphenylporphyrin auf der Oberfläche von ultradünnen MgO(001)‐Filmen durch Ladungstransfer ermöglicht wird. Es wird gezeigt, dass der Ladungszustand und dadurch der Metallierungszustand der Porphyrin‐Moleküle durch die Austrittsarbeit des MgO(001)/Ag(001)‐Substrats gezielt eingestellt werden können.
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Affiliation(s)
- Larissa Egger
- Institute of PhysicsNAWI GrazUniversity of GrazUniversitätsplatz 58010GrazÖsterreich
| | - Michael Hollerer
- Institute of PhysicsNAWI GrazUniversity of GrazUniversitätsplatz 58010GrazÖsterreich
| | - Christian S. Kern
- Institute of PhysicsNAWI GrazUniversity of GrazUniversitätsplatz 58010GrazÖsterreich
| | - Hannes Herrmann
- Institute of PhysicsNAWI GrazUniversity of GrazUniversitätsplatz 58010GrazÖsterreich
| | - Philipp Hurdax
- Institute of PhysicsNAWI GrazUniversity of GrazUniversitätsplatz 58010GrazÖsterreich
| | - Anja Haags
- Peter Grünberg Institute (PGI-3)Forschungszentrum Jülich52425JülichDeutschland
- Jülich Aachen Research Alliance (JARA)Fundamentals of Future Information Technology52425JülichDeutschland
- Experimentalphysik IV ARWTH Aachen University52074AachenDeutschland
| | - Xiaosheng Yang
- Peter Grünberg Institute (PGI-3)Forschungszentrum Jülich52425JülichDeutschland
- Jülich Aachen Research Alliance (JARA)Fundamentals of Future Information Technology52425JülichDeutschland
- Experimentalphysik IV ARWTH Aachen University52074AachenDeutschland
| | | | - Mathias Richter
- Physikalisch-Technische Bundesanstalt (PTB)10587BerlinDeutschland
| | - Serguei Soubatch
- Peter Grünberg Institute (PGI-3)Forschungszentrum Jülich52425JülichDeutschland
- Jülich Aachen Research Alliance (JARA)Fundamentals of Future Information Technology52425JülichDeutschland
| | - F. Stefan Tautz
- Peter Grünberg Institute (PGI-3)Forschungszentrum Jülich52425JülichDeutschland
- Jülich Aachen Research Alliance (JARA)Fundamentals of Future Information Technology52425JülichDeutschland
- Experimentalphysik IV ARWTH Aachen University52074AachenDeutschland
| | - Georg Koller
- Institute of PhysicsNAWI GrazUniversity of GrazUniversitätsplatz 58010GrazÖsterreich
| | - Peter Puschnig
- Institute of PhysicsNAWI GrazUniversity of GrazUniversitätsplatz 58010GrazÖsterreich
| | - Michael G. Ramsey
- Institute of PhysicsNAWI GrazUniversity of GrazUniversitätsplatz 58010GrazÖsterreich
| | - Martin Sterrer
- Institute of PhysicsNAWI GrazUniversity of GrazUniversitätsplatz 58010GrazÖsterreich
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4
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Egger L, Hollerer M, Kern CS, Herrmann H, Hurdax P, Haags A, Yang X, Gottwald A, Richter M, Soubatch S, Tautz FS, Koller G, Puschnig P, Ramsey MG, Sterrer M. Charge-Promoted Self-Metalation of Porphyrins on an Oxide Surface. Angew Chem Int Ed Engl 2021; 60:5078-5082. [PMID: 33245197 PMCID: PMC7986846 DOI: 10.1002/anie.202015187] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Indexed: 01/03/2023]
Abstract
Metalation and self-metalation reactions of porphyrins on oxide surfaces have recently gained interest. The mechanism of porphyrin self-metalation on oxides is, however, far from being understood. Herein, we show by a combination of results obtained with scanning tunneling microscopy, photoemission spectroscopy, and DFT computations, that the self-metalation of 2H-tetraphenylporphyrin on the surface of ultrathin MgO(001) films is promoted by charge transfer. By tuning the work function of the MgO(001)/Ag(001) substrate, we are able to control the charge and the metalation state of the porphyrin molecules on the surface.
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Affiliation(s)
- Larissa Egger
- Institute of PhysicsNAWI GrazUniversity of GrazUniversitätsplatz 58010GrazAustria
| | - Michael Hollerer
- Institute of PhysicsNAWI GrazUniversity of GrazUniversitätsplatz 58010GrazAustria
| | - Christian S. Kern
- Institute of PhysicsNAWI GrazUniversity of GrazUniversitätsplatz 58010GrazAustria
| | - Hannes Herrmann
- Institute of PhysicsNAWI GrazUniversity of GrazUniversitätsplatz 58010GrazAustria
| | - Philipp Hurdax
- Institute of PhysicsNAWI GrazUniversity of GrazUniversitätsplatz 58010GrazAustria
| | - Anja Haags
- Peter Grünberg Institute (PGI-3)Forschungszentrum Jülich52425JülichGermany
- Jülich Aachen Research Alliance (JARA)Fundamentals of Future Information Technology52425JülichGermany
- Experimentalphysik IV ARWTH Aachen University52074AachenGermany
| | - Xiaosheng Yang
- Peter Grünberg Institute (PGI-3)Forschungszentrum Jülich52425JülichGermany
- Jülich Aachen Research Alliance (JARA)Fundamentals of Future Information Technology52425JülichGermany
- Experimentalphysik IV ARWTH Aachen University52074AachenGermany
| | | | - Mathias Richter
- Physikalisch-Technische Bundesanstalt (PTB)10587BerlinGermany
| | - Serguei Soubatch
- Peter Grünberg Institute (PGI-3)Forschungszentrum Jülich52425JülichGermany
- Jülich Aachen Research Alliance (JARA)Fundamentals of Future Information Technology52425JülichGermany
| | - F. Stefan Tautz
- Peter Grünberg Institute (PGI-3)Forschungszentrum Jülich52425JülichGermany
- Jülich Aachen Research Alliance (JARA)Fundamentals of Future Information Technology52425JülichGermany
- Experimentalphysik IV ARWTH Aachen University52074AachenGermany
| | - Georg Koller
- Institute of PhysicsNAWI GrazUniversity of GrazUniversitätsplatz 58010GrazAustria
| | - Peter Puschnig
- Institute of PhysicsNAWI GrazUniversity of GrazUniversitätsplatz 58010GrazAustria
| | - Michael G. Ramsey
- Institute of PhysicsNAWI GrazUniversity of GrazUniversitätsplatz 58010GrazAustria
| | - Martin Sterrer
- Institute of PhysicsNAWI GrazUniversity of GrazUniversitätsplatz 58010GrazAustria
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5
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Fernández CC, Franke M, Steinrück HP, Lytken O, Williams FJ. Demetalation of Surface Porphyrins at the Solid-Liquid Interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:852-857. [PMID: 33400533 DOI: 10.1021/acs.langmuir.0c03197] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Understanding the factors that control the demetalation of surface porphyrins at the solid-liquid interface is important as the molecular properties of porphyrins are largely determined by their metal centers. In this work, we used X-ray photoelectron spectroscopy (XPS) to follow the demetalation of Zn and Cd tetraphenylporphyrin molecules (ZnTPP and CdTPP) adsorbed as three-monolayer-thin multilayer films on Au(111), by exposing the molecular layers to acidic aqueous solutions. We found that porphyrin molecules at the solid-liquid interface are less prone to lose their metal center than molecules in solution. We propose that this behavior is due to either the incoming protons provided by the solution or the outgoing metal ion having to pass through the hydrophobic porphyrin multilayers where they cannot be solvated. Our results are relevant for the design of molecular devices based on porphyrin molecules adsorbed on solid surfaces.
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Affiliation(s)
- Cynthia C Fernández
- Departamento de Química Inorgánica, Analítica y Química Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- Instituto de Química Física de los Materiales, Medio Ambiente y Energía INQUIMAE, CONICET, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Matthias Franke
- Lehrstuhl für Physikalische Chemie II, Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Hans-Peter Steinrück
- Lehrstuhl für Physikalische Chemie II, Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Ole Lytken
- Lehrstuhl für Physikalische Chemie II, Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Federico J Williams
- Departamento de Química Inorgánica, Analítica y Química Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- Instituto de Química Física de los Materiales, Medio Ambiente y Energía INQUIMAE, CONICET, Universidad de Buenos Aires, Buenos Aires, Argentina
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6
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Xiang F, Schmitt T, Raschmann M, Schneider MA. Adsorption and self-assembly of porphyrins on ultrathin CoO films on Ir(100). BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2020; 11:1516-1524. [PMID: 33094085 PMCID: PMC7554680 DOI: 10.3762/bjnano.11.134] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 09/22/2020] [Indexed: 06/11/2023]
Abstract
Porphyrins represent a versatile class of molecules, the adsorption behavior of which on solid surfaces is of fundamental interest due to a variety of potential applications. We investigate here the molecule-molecule and molecule-substrate interaction of Co-5,15-diphenylporphyrin (Co-DPP) and 2H-tetrakis(p-cyanophenyl)porphyrin (2H-TCNP) on one bilayer (1BL) and two bilayer (2BL) thick cobalt oxide films on Ir(100) by scanning tunneling microscopy (STM) and density functional theory (DFT). The two substrates differ greatly with respect to their structural and potential-energy landscape corrugation with immediate consequences for adsorption and self-assembly of the molecules studied. On both films, an effective electronic decoupling from the metal substrate is achieved. However, on the 1BL film, Co-DPP molecules are sufficiently mobile at 300 K and coalesce to self-assembled molecular islands when cooled to 80 K despite their rather weak intermolecular interaction. In contrast, on the 2BL film, due to the rather flat potential landscape, molecular rotation is thermally activated, which effectively prevents self-assembly. The situation is different for 2H-TCNPP, which, due to the additional functional anchoring groups, does not self-assemble on the 1BL film but forms self-assembled compact islands on the 2BL film. The findings demonstrate the guiding effect of the cobalt oxide films of different thickness and the effect of functional surface anchoring.
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Affiliation(s)
- Feifei Xiang
- Solid State Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91058 Erlangen, Germany
| | - Tobias Schmitt
- Solid State Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91058 Erlangen, Germany
| | - Marco Raschmann
- Solid State Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91058 Erlangen, Germany
| | - M Alexander Schneider
- Solid State Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91058 Erlangen, Germany
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7
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Wähler T, Schuster R, Libuda J. Self-Metalation of Anchored Porphyrins on Atomically Defined Cobalt Oxide Surfaces: In situ Studies by Surface Vibrational Spectroscopy. Chemistry 2020; 26:12445-12453. [PMID: 32333716 PMCID: PMC7590103 DOI: 10.1002/chem.202001331] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Indexed: 12/20/2022]
Abstract
Metalation of anchored porphyrins is essential for their functionality at hybrid interfaces. In this work, we have studied the anchoring and metalation of a functionalized porphyrin derivative, 5-(4-carboxyphenyl)-10,15,20-triphenylporphyrin (MCTPP), on an atomically-defined CoO(100) film under ultrahigh vacuum (UHV) conditions. We follow both the anchoring to the oxide surface and the self-metalation by surface Co2+ ions via infrared reflection absorption spectroscopy (IRAS). At 150 K, MCTPP multilayer films adsorb molecularly on CoO(100) without anchoring to the surface. Upon heating to 195 K, the first layer of porphyrin molecules anchors via formation of a bridging surface carboxylate. Above 460 K, the MCTPP multilayer desorbs and only the anchored monolayer resides on the surface up to temperatures of 600 K approximately. The orientation of anchored MCTPP depends on the surface coverage. At low coverage, the MCTPP adopts a nearly flat-lying geometry, whereas an upright standing film is formed near the multilayer coverage. Self-metalation of MCTPP depends critically on the surface temperature, the coverage and on the molecular orientation. At 150 K, metalation is largely suppressed, while the degree of metalation increases with increasing temperature and reaches a value of around 60 % in the first monolayer at 450 K. At lower coverage higher metalation fractions (85 % and above) are observed, similar as for increasing temperature.
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Affiliation(s)
- Tobias Wähler
- Interface Research and CatalysisErlangen Center for Interface Research and Catalysis (ECRC)Friedrich-Alexander-Universität Erlangen-NürnbergEgerlandstraße 391058ErlangenGermany
| | - Ralf Schuster
- Interface Research and CatalysisErlangen Center for Interface Research and Catalysis (ECRC)Friedrich-Alexander-Universität Erlangen-NürnbergEgerlandstraße 391058ErlangenGermany
| | - Jörg Libuda
- Interface Research and CatalysisErlangen Center for Interface Research and Catalysis (ECRC)Friedrich-Alexander-Universität Erlangen-NürnbergEgerlandstraße 391058ErlangenGermany
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