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Nuić L, Panić B, Pereković LK, Rakić IŠ, Kralj M, Mihanović A, Vančik H, Biljan I. Polymerization of aromatic dinitroso derivatives initiated by nitroso-terminated monolayer on Au(111) surface: Insights from ellipsometry, AFM and nano-FTIR spectroscopy. POLYMER 2023. [DOI: 10.1016/j.polymer.2023.125795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
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2
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Liu ZX, Yang L, Chen YG, Tian ZY, Yang ZY. Noncovalent wedging effect catalyzed the cis to syn transformation of a surface-adsorbed polymer backbone toward an unusual thermodynamically stable supramolecular product. Phys Chem Chem Phys 2022; 24:30010-30016. [PMID: 36472299 DOI: 10.1039/d2cp04184g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The significant influence of noncovalent interactions on catalytic processes has been recently appreciated but is still in its infancy. In this report, it is found that wedging Me-PTCDI (small-molecule) between the alkyl chains of PffBT4T-2OD (polymer) and a graphite substrate can reduce the energy barrier of flipping over the surface-adsorbed alkylthiophene group from the cis to syn conformation, revealing the catalytic role of Me-PTCDI via a noncovalent wedging effect. The wedging of Me-PTCDI brings the interactions between the alkyl chains and substrate to a very weak level by lifting up the alkyl chains, which eliminates the major hindrance of the flipping process to one main factor: the torsion of the dihedral angles of the thiophene group. The Me-PTCDI/syn PffBT4T-2OD arrangement shows unusual stability compared to the cis one because the syn conformation allows the alkyl chains to construct dense lamella and facilitates interactions between Me-PTCDI and the syn PffBT4T-2OD backbones. The results are helpful for boosting the development of noncovalent catalysis and bottom-up fabrications toward devices functionalized at a molecular level.
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Affiliation(s)
- Zhi-Xuan Liu
- School of Chemical Science, University of Chinese Academy of Sciences, 19A Yuquanlu, Beijing, 100049, P. R. China.
| | - Ling Yang
- School of Chemical Science, University of Chinese Academy of Sciences, 19A Yuquanlu, Beijing, 100049, P. R. China.
| | - Yong-Gang Chen
- Dalian University of Technology, No. 2 Linggong road, Dalian, 116024, Liaoning province, P. R. China
| | - Zhi-Yuan Tian
- School of Chemical Science, University of Chinese Academy of Sciences, 19A Yuquanlu, Beijing, 100049, P. R. China.
| | - Zhi-Yong Yang
- School of Chemical Science, University of Chinese Academy of Sciences, 19A Yuquanlu, Beijing, 100049, P. R. China.
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Franco-Cañellas A, Duhm S, Gerlach A, Schreiber F. Binding and electronic level alignment of π-conjugated systems on metals. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2020; 83:066501. [PMID: 32101802 DOI: 10.1088/1361-6633/ab7a42] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
We review the binding and energy level alignment of π-conjugated systems on metals, a field which during the last two decades has seen tremendous progress both in terms of experimental characterization as well as in the depth of theoretical understanding. Precise measurements of vertical adsorption distances and the electronic structure together with ab initio calculations have shown that most of the molecular systems have to be considered as intermediate cases between weak physisorption and strong chemisorption. In this regime, the subtle interplay of different effects such as covalent bonding, charge transfer, electrostatic and van der Waals interactions yields a complex situation with different adsorption mechanisms. In order to establish a better understanding of the binding and the electronic level alignment of π-conjugated molecules on metals, we provide an up-to-date overview of the literature, explain the fundamental concepts as well as the experimental techniques and discuss typical case studies. Thereby, we relate the geometric with the electronic structure in a consistent picture and cover the entire range from weak to strong coupling.
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Affiliation(s)
- Antoni Franco-Cañellas
- Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany
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Wang Y, Hou J, Eguchi K, Nanjo C, Takaoka T, Sainoo Y, Awaga K, Komeda T. Structural, Electronic, and Magnetic Properties of Cobalt Tetrakis (Thiadiazole) Porphyrazine Molecule Films on Au(111). ACS OMEGA 2020; 5:6676-6683. [PMID: 32258903 PMCID: PMC7114880 DOI: 10.1021/acsomega.9b04453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 03/05/2020] [Indexed: 06/11/2023]
Abstract
We investigated the structural and electronic/spin configurations of a film of the Co tetrakis(1,2,5-thiadiazole) porphyrazine (CoTTDPz) molecule adsorbed on the Au(111) surface by a scanning tunneling microscope (STM). CoTTDPz has a structure similar to that of the Co phthalocyanine molecule, but the benzene ring of the isoindole of the phthalocyanine molecule is replaced by the pentagon moiety of 1,2,5-thiadiazoles that has an S atom at the apex. We find an ordered molecular lattice with a threefold symmetry where a nearest-neighbor distance of 1.30 nm was measured, which is significantly smaller than that observed for the metal Pc molecule. The unit cell of the lattice contains two molecules that are rotated by 60° relative to each other. With the configuration achieved by this rotation, the neighboring molecules can form a stronger interaction through bonding between the S atom at the apex of one molecule and the N atom of the other (the N atom that is bridging the thiadiazoles). The strong interaction between the molecule and the substrate appears in the spin state examined by the detection of the Kondo resonance, which is formed by the screening of an isolated spin by the conduction electron. Even though the existence of the spin was confirmed for the bulk and thick films of this molecule, no Kondo features are detected for the molecules in the first, second, and third layers of the films. However, the isolated molecule in the third layer showed an intriguing combination of the Kondo feature and an inelastic excitation feature caused by a spin-flip process.
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Affiliation(s)
- Yu Wang
- Department
of Chemistry, Graduate School of Science, Tohoku University, Aramaki-Aza-Aoba, Aoba-Ku, Sendai 980-8578, Japan
- Institute
of Multidisciplinary Research for Advanced Materials (IMRAM, Tagen), Tohoku University, 2-1-1, Katahira, Aoba-Ku, Sendai 980-0877, Japan
| | - Jie Hou
- Department
of Chemistry, Graduate School of Science, Tohoku University, Aramaki-Aza-Aoba, Aoba-Ku, Sendai 980-8578, Japan
- Institute
of Multidisciplinary Research for Advanced Materials (IMRAM, Tagen), Tohoku University, 2-1-1, Katahira, Aoba-Ku, Sendai 980-0877, Japan
| | - Keitaro Eguchi
- Department
of Chemistry & Research Center for Materials Science, Nagoya University, Chikusa-ku, Nagoya 464-8602, Japan
| | - Chihiro Nanjo
- Department
of Chemistry & Research Center for Materials Science, Nagoya University, Chikusa-ku, Nagoya 464-8602, Japan
| | - Tsuyoshi Takaoka
- Department
of Chemistry, Graduate School of Science, Tohoku University, Aramaki-Aza-Aoba, Aoba-Ku, Sendai 980-8578, Japan
- Institute
of Multidisciplinary Research for Advanced Materials (IMRAM, Tagen), Tohoku University, 2-1-1, Katahira, Aoba-Ku, Sendai 980-0877, Japan
| | - Yasuyuki Sainoo
- Department
of Chemistry, Graduate School of Science, Tohoku University, Aramaki-Aza-Aoba, Aoba-Ku, Sendai 980-8578, Japan
- Institute
of Multidisciplinary Research for Advanced Materials (IMRAM, Tagen), Tohoku University, 2-1-1, Katahira, Aoba-Ku, Sendai 980-0877, Japan
| | - Kunio Awaga
- Department
of Chemistry & Research Center for Materials Science, Nagoya University, Chikusa-ku, Nagoya 464-8602, Japan
| | - Tadahiro Komeda
- Institute
of Multidisciplinary Research for Advanced Materials (IMRAM, Tagen), Tohoku University, 2-1-1, Katahira, Aoba-Ku, Sendai 980-0877, Japan
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Teyssandier J, Mali KS, De Feyter S. Halogen Bonding in Two-Dimensional Crystal Engineering. ChemistryOpen 2020; 9:225-241. [PMID: 32071832 PMCID: PMC7011184 DOI: 10.1002/open.201900337] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 01/14/2020] [Indexed: 12/11/2022] Open
Abstract
Halogen bonds, which provide an intermolecular interaction with moderate strength and high directionality, have emerged as a promising tool in the repertoire of non-covalent interactions. In this review, we provide a survey of the literature where halogen bonding was used for the fabrication of supramolecular networks on solid surfaces. The definitions of, and the distinction between halogen bonding and halogen-halogen interactions are provided. Self-assembled networks formed at the solution/solid interface and at the vacuum-solid interface, stabilized in part by halogen bonding, are discussed. Besides the broad classification based on the interface at which the systems are studied, the systems are categorized further as those sustained by halogen-halogen and halogen-heteroatom contacts.
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Affiliation(s)
- Joan Teyssandier
- Division of Molecular Imaging and Photonics Department of ChemistryKU Leuven-University of LeuvenCelestijnenlaan 200F3001LeuvenBelgium
| | - Kunal S. Mali
- Division of Molecular Imaging and Photonics Department of ChemistryKU Leuven-University of LeuvenCelestijnenlaan 200F3001LeuvenBelgium
| | - Steven De Feyter
- Division of Molecular Imaging and Photonics Department of ChemistryKU Leuven-University of LeuvenCelestijnenlaan 200F3001LeuvenBelgium
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Lexow M, Massicot S, Maier F, Steinrück HP. Stability and Exchange Processes in Ionic Liquid/Porphyrin Composite Films on Metal Surfaces. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2019; 123:29708-29721. [PMID: 31867088 PMCID: PMC6913898 DOI: 10.1021/acs.jpcc.9b08531] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2019] [Revised: 11/12/2019] [Indexed: 06/10/2023]
Abstract
In light of increasing interest in the development of organic-organic multicomponent heterostructures on metals, this molecular-scale study investigates prototypical composite systems of ultrathin porphyrin and ionic liquid (IL) films on metallic supports under well-defined ultrahigh vacuum conditions. By means of angle-resolved X-ray photoelectron spectroscopy, we investigated the adsorption, stability, and thermal exchange of the resulting films after sequential physical vapor deposition of the free-base porphyrin 5,10,15,20-tetraphenylporphyrin, 2H-TPP, and the IL 1-methyl-3-octylimidazolium hexafluorophosphate, [C8C1Im][PF6], on Ag(111) and Au(111). 2H-TPP shows two-dimensional growth of up to two closed molecular layers on Ag(111) and Au(111) and three-dimensional island growth for thicker films. IL films on top of a monolayer of 2H-TPP exhibit Stranski-Krastanov-like growth and are stable up to 385 K. The 2H-TPP layer leads to destabilization of the IL films, compared to the IL in direct contact with the bare metals, by inhibiting the specific adsorption of the ions on the metal surfaces. When the porphyrin is deposited on top of [C8C1Im][PF6] at low temperature, the 2H-TPP molecules adsorb on top of the IL film at first but replace the IL at the IL/metal interfaces upon heating above 240 K. This exchange process is most likely driven by the higher adsorption energy of 2H-TPP on Ag(111) and Au(111) surfaces, as compared to the IL. The behavior observed on Ag(111) and Au(111) is identical. The results are highly relevant for the stability of porphyrin/IL-based thin film catalyst systems and molecular devices, and more generally, stacked organic multilayer architectures.
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Deimel PS, Feulner P, Barth JV, Allegretti F. Spatial decoupling of macrocyclic metal-organic complexes from a metal support: a 4-fluorothiophenol self-assembled monolayer as a thermally removable spacer. Phys Chem Chem Phys 2019; 21:10992-11003. [PMID: 31106802 DOI: 10.1039/c9cp01583c] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The precise control over the electronic properties and function of metal centres in metal-organic complexes such as metallo-porphyrins (MPs) and metallo-phthalocyanines (MPcs) holds promise for their targeted application in, e.g., nanoscale chemical conversion devices and molecular sensors. However, when immobilizing these flat chelate complexes on solid supports, the influence of the latter on the metal centres can decisively alter their chemistry and functional properties, e.g. through charge transfer and orbital hybridization on metal substrates. In the present work we explore a simple strategy to both spatially and electronically decouple prototypical MP and MPc compounds from a Ag(111) surface, by preventing direct physical contact with the underlying support via insertion of a self-assembled monolayer (SAM) of 4-fluorothiophenol (4-FTP). This spacer layer can be important to preserve the molecular properties of adsorbed MPs and MPcs and to design hybrid functional systems of increasing sophistication such as stacked multilayer architectures. Herein, we show that at low temperature (∼150 K) the 4-FTP SAM on Ag(111) can indeed serve to decouple iron-phthalocyanine (FePc) and ruthenium-tetraphenylporphyrin (Ru(CO)TPP) monolayers from the Ag(111) surface. When the temperature is increased, however, the system's configuration breaks down, resulting in an inverted stacking followed by the complete removal of 4-FTP at elevated temperatures. The SAM can thus play the role of a thermally removable spacer. We elucidate the structural and chemical evolution of the organic double-layer system by combination of X-ray photoelectron spectroscopy (XPS), temperature-programmed XPS (TP-XPS), temperature-programmed desorption (TPD), and low-energy electron diffraction (LEED) measurements.
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Affiliation(s)
- Peter S Deimel
- Physics Department E20, Technical University of Munich, 85748 Garching, Germany.
| | - Peter Feulner
- Physics Department E20, Technical University of Munich, 85748 Garching, Germany.
| | - Johannes V Barth
- Physics Department E20, Technical University of Munich, 85748 Garching, Germany.
| | - Francesco Allegretti
- Physics Department E20, Technical University of Munich, 85748 Garching, Germany.
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Sabik A, Mazur P, Gołek F, Trembulowicz A, Antczak G. Phthalocyanine arrangements on Ag(100): From pure overlayers of CoPc and F 16CuPc to bimolecular heterostructure. J Chem Phys 2018; 149:144702. [PMID: 30316254 DOI: 10.1063/1.5050377] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We have utilized scanning tunneling microscopy (STM) and low energy electron diffraction to determine the structural properties of two types of metal-phthalocyanines (MPcs), i.e., cobalt-phthalocyanine (CoPc) and hexadecafluorinated copper-phthalocyanine (F16CuPc) on the Ag(100) surface. For coverage close to one monolayer, both systems form long-range ordered structures with square unit cells. The size and rotation of the unit cell with respect to the silver lattice depend on the chemical composition of MPc. Both types of molecules prefer adsorption with around a 30° angle between the molecular axis and the [011] silver direction. The CoPcs mainly arrange in a (5 × 5)R0 phase; however, two additional local arrangements, a 26 × 26 R 1 1 ○ and a (7 × 7)R0, were detected by STM. The F16CuPcs form a 29 × 29 R 2 2 ○ structure. The co-adsorption of CoPc and F16CuPc on the Ag(100) surface in a 1:1 ratio leads to the formation of a compositionally ordered chessboard-like 5 2 × 5 2 R 4 5 ○ structure. During filled states imaging, the different appearance of the central part of each MPc allows us to distinguish CoPcs from F16CuPcs. Regardless of the applied voltage polarity, the ligands of F16CuPcs appear brighter than the ligands of CoPcs.
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Affiliation(s)
- Agata Sabik
- Department of Physics and Astronomy, Institute of Experimental Physics, University of Wrocław, Wrocław, Poland
| | - Piotr Mazur
- Department of Physics and Astronomy, Institute of Experimental Physics, University of Wrocław, Wrocław, Poland
| | - Franciszek Gołek
- Department of Physics and Astronomy, Institute of Experimental Physics, University of Wrocław, Wrocław, Poland
| | - Artur Trembulowicz
- Department of Physics and Astronomy, Institute of Experimental Physics, University of Wrocław, Wrocław, Poland
| | - Grażyna Antczak
- Department of Physics and Astronomy, Institute of Experimental Physics, University of Wrocław, Wrocław, Poland
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