1. Structural phases of ordered FePc-nanochains self-assembled on Au(110)Betti Maria Grazia, Pierluigi Gargiani, Carlo Mariani, Roberto Biagi, Jun Fujii, Giorgio Rossi, Andrea Resta, Stefano Fabris, Sara Fortuna, Xavier Torrelles, Manvendra Kumar, Maddalena Pedio, 2012, original scientific article Abstract: Iron-phthalocyanine molecules deposited on the Au(110) reconstructed channels assemble into one-dimensional molecular chains, whose spatial distribution evolves into different structural phases at increasing molecular density. The plasticity of the Au channels first induces an ordered phase with a 5×5 symmetry, followed by a second long-range ordered structure composed by denser chains with a 5×7 periodicity with respect to the bare Au surface, as observed in the low-energy electron-diffraction (LEED) and grazing incidence X-ray diffraction (GIXRD) patterns. The geometry of the FePc molecular assemblies in the Au nanorails is determined by scanning tunneling microscopy (STM). For the 5×7 phases, the GIXRD analysis identifies a “4-3” rows profile along the [001] direction in the Au surface and an on-top FePc adsorption site, further confirmed by density functional theory (DFT) calculations. The latter also reveals the electronic mixing of the interface states. The chain assembly is driven by the molecule–molecule interaction and the chains interact with the Au nanorails via the central metal atom, while the chain–chain distance in the different structural phases is primarily driven by the plasticity of the Au surface.
Found in: osebi
Keywords: STM, LEED, DFT, density functional theory, phthalocyanine, Au(110), gold, surface
Published: 13.10.2016; Views: 4038; Downloads: 0
 Fulltext (1,33 MB) |
2. Spin and orbital configuration of metal phthalocyanine chains assembled on the Au(110) surfaceGargiani Pierluigi, Giorgio Rossi, Roberto Biagi, Valdis Corradini, Maddalena Pedio, Sara Fortuna, Arrigo Calzolari, Stefano Fabris, Julio Criginski Cezar, N. B. Brookes, Maria Grazia Betti, 2013, original scientific article Abstract: The spin and orbital configuration of magnetic metal phthalocyanines (MPcs) deposited on metallic substrates are strongly influenced by the rehybridization of the molecular states with the underlying metal. FePc, CoPc, and CuPc isolated molecules are archetypal systems to investigate the interrelationship between magnetic moments and orbital symmetry after deposition on a metallic substrate. MPcs form long-range ordered chains self-assembled along the reconstructed channels of the Au(110) surface. X-ray magnetic circular dichroism from the L2,3 absorption edges of Fe, Co, and Cu shows that the orbital and spin configuration are strongly modified upon adsorption on the Au(110) surface if the orbitals responsible of the magnetic moment are involved in the interaction process. The magnetic moment for a single layer of molecular chains is completely quenched for the CoPc molecules, fully preserved for the CuPc and reduced for the FePc ones. The modified magnetic configuration is confined to the very interface layer, i.e., to the MPc molecules bound to the metal substrate up to the compact packing of the single layer. The different response can be rationalized in terms of the symmetry/orientation of the metal-ion d states interacting with the substrate states, as indicated by density functional theory calculations in agreement with experimental findings.
Found in: osebi
Keywords: phthalocyanine, Au(110), gold, self-assembly, pattern, configuration, density functional theory, DFT, CuPc, FePc
Published: 12.10.2016; Views: 3983; Downloads: 0
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3. Introduction to Electronic Properties and Dynamics of Organic Complexes as Self‐Assembled MonolayersMaddalena Pedio, 2017, independent scientific component part or a chapter in a monograph Abstract: Self‐assembled monolayers (SAMs) of organic‐conjugated transition metal complexes on surfaces is a focus of both device engineering and basic science, since it is a key factor in nearly all important aspects of device performances, including operation voltages, degradation, and efficiency. The huge amount of literature results related to the first monolayer, and reorganization and self‐assembling processes are due to the general accepted result that structural and chemical properties of the first monolayer are the key parameters for controlled thin film growth. Optical and magneto‐electronic properties are intimately connected, and the accurate determination of electronic levels, excitation, and relaxation dynamics is mandatory for the optimization of electronic, photovoltaic, and opto‐electronic devices. Quite a number of electronic states is generated by the interaction of light with
complex organic molecules. Time‐resolved spectroscopies are a new investigation tool
that gives the possibility of correctly addressing their origin and life time. Examples of prototypical systems are presented and discussed. We review on complementary techniques, trying to single out how different approaches are fundamental to fully characterize
these complex systems.
Found in: osebi
Keywords: self‐assembled monolayer (SAM), surface structures molecular layers, nanotechnology, electronic properties, spectroscopies, time resolved
Published: 12.06.2017; Views: 3828; Downloads: 201
Fulltext (5,78 MB) |
4. Conclusively Addressing the CoPc Electronic Structure: A Joint Gas- Phase and Solid-State Photoemission and Absorption Spectroscopy StudyMarcello Coreno, Monica de Simone, Ieva Bidermane, Y. Sassatelli, R. Ovsyannikov, Erika Giangrisostomi, C. Grazioli, J. Lüder, Valeria Lanzillotto, I.E. Brumboiu, Teng Zhang, Barbara Ressel, Matija Stupar, Maddalena Pedio, Petra Rudolf, Barbara Brena, Carla Puglia, 2017, original scientific article Found in: osebi
Keywords: Cobalt Phtalocyanine, photoemission spectroscopy, gas phase, solid state
Published: 07.02.2018; Views: 3512; Downloads: 0
Fulltext (1,38 MB) |
