Research Projects around the SMALL network

Large functional molecules on surfaces for sensing and recognition
Karsten Handrup (supervisor: James O'Shea)
School of Physics & Astronomy, University of Nottingham UK

This project seeks to harness the molecular recognition functionality of large complex molecules borrowed from nature e.g. porphyrins, coordination complexes and proteins, by the formation of functional monolayers on surfaces. These surfaces will be prepared by in-situ electrospray deposition under ultra-high vacuum (UHV) conditions, and will be characterised in terms of the chemical, structural and electronic effects of molecular recognition interactions. The project will use experimental surface science techniques including scanning tunnelling microscopy (STM), photoelectron spectroscopy (PES) and low energy electron diffraction based in our laboratory at Nottingham and other nodes of the SMALL network. In addition, a large part of the project will involve the use of synchrotron radiation-based photoemission and x-ray absorption spectroscopies at European facilities.

Molecular chirality and dynamics on surfaces
Ajigul Nuermaimaiti (supervisor: Trolle Linderoth)
Aarhus University, Denmark

The chirality or handedness or molecules is a fascinating topic with wide implications within pharmaceuticals, sensing and “origin of life”, all related to the fact that Nature is homochiral in the sense that natural biomolecules only occur in one of two possible chiral forms. The binding and organization of chiral molecules on surfaces is crucially important within all these fields and there has been an explosive development in understanding over the last decade, not least brought about by the possibility of imaging chiral adsorbates directly using the technique of Scanning Tunneling Microscopy (STM). In the project we will explore fundamental questions related to chiral adsorption on surfaces, including how chiral (bio-)molecules bind to specially designed metal surfaces exhibiting chiral recognition sites, and use fast-scanning STM movies to elucidate how conformational chiral switching can lead to novel chiral accommodation and induction mechanisms by molecular recognition processes.

Molecular recognition in the adsorption and reaction of gaseous reactants over supramolecular structures at surfaces
Olesia Snezhkova (supervisor: Achim Schnadt)
Lund University, Sweden

Project: In catalysis, molecular recognition is a highly important element if a high selectivity of the catalytic process is to be achieved. The present project aims at, on a fundamental level, investigating how molecular recognition can be realised over supramolecular structures at surfaces, composed of organic and metallic components. The project will use experimental surface science techniques, and a large part of the experimental work will be performed at the National Swedish Synchrotron Radiation Facility MAX-lab (http://www.maxlab.lu.se). In particular, use will be made of a novel x-ray photoelectron spectroscopy instrument for the investigation of catalytic surfaces under reaction and ultrahigh vacuum (UHV) conditions. An important part of the project will be the collaboration with Synthetic Chemists at Lund University to provide the necessary components for the supramolecular structures.

Unravelling the mysteries of metal oxide-water interfaces: theory
Gabriele Tocci (supervisor: Angelos Michaelides)
UCL, UK

Metal oxide interfaces with water are incredibly important in our everyday life (eg corrosion) as well as in a number of emerging technologies such as light harvesting to produce H₂ as an alternative fuel. Nevertheless, an atomic level understanding of the key processes that limit performance is still lacking. To achieve this understanding will require the application of experimental and theoretical techniques that examine structures with atomic precision under realistic conditions, i.e. covered with liquid water. This project aims to acquire this understanding at an unprecedented level through a combination of surface X-ray diffraction (SXRD) and scanning tunnelling microscopy (STM) experiments along with state-of-the-art first principles simulations.

A label-free nanosensor system based on molecular recognition
Shilpi Chaudhary (supervisor: Andre Bergstrand)
ENI, Sweden

Nanosensors are already today in practical use in many applications. The principal detection scheme is often based on molecular recognition between a target molecule and a suitable binding molecular structure, a kind of a key-lock system. However, the successful binding event is most often signalled by the use of a reporter (label) system, such as a label molecule, being bound to the target molecule. The function of the label molecule is to report when the target molecule have been bound. Such reporting systems may interfere with the binding event and hence create false signals or even worse, fundamentally change the binding situation. Hence, in this research project we will investigate a label-free detection scheme that will circumvent the discussed problems allowing a reporting event without the use of a label.

The Role of Solvents in Chiral Recognition
Filled (supervisor: Georg Held)
University of Reading, UK

The projects at Reading, "The Role of Solvents in Chiral Recognition" and "Anchoring Molecular Tweezers on Surfaces" aim for a better understanding of molecular recognition in heterogeneous catalysts in solution and the design of novel sensors based on “molecular tweezers” interacting with polymer chains on solid surfaces.

Anchoring Molecular Tweezers on Surfaces
Filled (supervisor: Howard Colquhoun)
University of Reading, UK

The projects at Reading, "The Role of Solvents in Chiral Recognition" and "Anchoring Molecular Tweezers on Surfaces" aim for a better understanding of molecular recognition in heterogeneous catalysts in solution and the design of novel sensors based on “molecular tweezers” interacting with polymer chains on solid surfaces.

Unravelling the mysteries of metal oxide-water interfaces: experiment
Marco Nicotra (supervisor: Geoff Thornton)
UCL, UK

Metal oxide interfaces with water are incredibly important in our everyday life (eg corrosion) as well as in a number of emerging technologies such as light harvesting to produce H₂ as an alternative fuel. Nevertheless, an atomic level understanding of the key processes that limit performance is still lacking. To achieve this understanding will require the application of experimental and theoretical techniques that examine structures with atomic precision under realistic conditions, i.e. covered with liquid water. This project aims to acquire this understanding at an unprecedented level through a combination of surface X-ray diffraction (SXRD) and scanning tunnelling microscopy (STM) experiments along with state-of-the-art first principles simulations.

Activation of hydrocarbons using surface-bonded molecular catalysts
Ekaterina Bolbat (supervisor: Ola Wendt)
Lund University, Sweden

This project aims to develop catalysts for direct functionalisation of hydrocarbons and to heterogenise them by surface anchoring, and investigate the catalytic activity in e.g. C–C bond forming reactions. Characterisation use ultrahigh vacuum (UHV) and in situ surface science techniques.

Electronic properties of metal-supported molecular nanostructures
Luigi Terracciano (supervisor: Roberto Otero)
UAM, Spain

The fast development of organic electronics is making necessary an in-depth understanding of organic/metal interfaces. Molecules with electron-accepting (large electron-affinity) or electron-donating (small ionization potential) character display interesting electrical and optical properties which can be used in organic solar cells, light-emission diodes (OLEDs) or field-effect transistors (OFETs). All these devices, however, contain at some point one or more organic/metal interface, which in many cases modifies and thus determines the electronic properties of the organic films. Our previous investigations have revealed a close relation between the electronic properties of the interface and its structure at the nanoscale, which can be crucial for the performance of future organic-based devices. The aim of this project is to find further relations between the electronic properties of metal-supported molecular nanostructures and the intermolecular interactions that hold them together, by using a unique combination of surface science techniques, which addresses structural (LEED, STM), chemical (AES, XPS) and electronic (XPS, STS) properties of the same sample.

Magnetic properties of supramolecular networks on surfaces
Flavio Pendolino (supervisor: Roberto Otero)
UAM, Spain

Materials with magnetic properties based on molecular species or polymers had attracted the attention of the research community in recent years. These materials can be obtained by constructing charge transfer salts combining molecules and metallic centres. The predicted properties of such molecular-based magnetic materials, particularly in combination with other physical properties associated with molecules and polymers, may open the opportunity for their use in future generations of electronic, magnetic, and/or photonic devices. Currently, the necessary step to develop such devices is to control the synthesis and the organization of this kind of organic materials on surfaces. Such structure depends on a number of competing interactions between the functional molecular groups, the interaction with the substrate and the adsorbed metal centres. The research will involve using surface science methods to grow and characterize the supramolecular networks in ultra-high vacuum (UHV). The experiments will involve the use of different surface science technique including scanning tunneling microscopy and spectroscopy.

Multiscale simulations of chiral monolayers at metal surfaces
Victor Gonzalo Ruiz López (supervisor: Alexandre Tkatchenko)
FHI Berlin, Germany

Chirality (handedness) is a property of asymmetry important in several branches of science. Enantioselectivity is the chemical selectivity towards a specific chiral form. As such, enantioselectivity lies at the very centre of the pharmaceuticals, agrochemicals, and fine chemical industries, since many relevant products of these industries are not only chiral, but the different chiral forms of the products often also affect the body and/or the environment in dramatically different ways (a benign example being the different taste of lemons and oranges). The research project at the Fritz-Haber-Institut in Berlin concerns the development of new computational methods for multiscale simulations of chiral monolayers at metal surfaces. The first goal is to develop novel approaches for an accurate treatment of molecule - surface and molecule -molecule interactions (e.g., van der Waals forces and hydrogen bonding). The second is to link electronic structure calculations to kinetic Monte Carlo simulations to include ensemble and time-scale effects and enable fully ab initio treatment of configurational and vibrational entropy. This project will be carried out in close collaboration with leading experimental groups in the SMALL network.

Multiscale simulations of chiral monolayers at metal surfaces
Vivekanand Gobre (supervisor: Alexandre Tkatchenko)
FHI Berlin, Germany

Chirality (handedness) is a property of asymmetry important in several branches of science. Enantioselectivity is the chemical selectivity towards a specific chiral form. As such, enantioselectivity lies at the very centre of the pharmaceuticals, agrochemicals, and fine chemical industries, since many relevant products of these industries are not only chiral, but the different chiral forms of the products often also affect the body and/or the environment in dramatically different ways (a benign example being the different taste of lemons and oranges). The research project at the Fritz-Haber-Institut in Berlin concerns the development of new computational methods for multiscale simulations of chiral monolayers at metal surfaces. The first goal is to develop novel approaches for an accurate treatment of molecule - surface and molecule -molecule interactions (e.g., van der Waals forces and hydrogen bonding). The second is to link electronic structure calculations to kinetic Monte Carlo simulations to include ensemble and time-scale effects and enable fully ab initio treatment of configurational and vibrational entropy. This project will be carried out in close collaboration with leading experimental groups in the SMALL network.

Electronic structure of supported porphyrin derivatives in a realistic environment : a DFT study
Torsten Houwaart (supervisor: Marie-Laure Bocquet)
ENS Lyon, France

Through a concomitant collaboration with STM experimentalists and organic chemists of the SMALL network, the goal of the PhD project is to model with DFT framework complex metallo-organic interfaces such as biomimetic systems likes porphyrins (metallo and/or ligated forms) on coinage metal surfaces (Cu,Ag, Au). The self-assembled porphyrin network is a promising material for the next generation of nanoelectronic devices. By capturing a transition metal atom, the porphyrins indeed allow to decouple and order nuclear spins on a metallic surface. The metalloporphyrins are thus open-shell and it remains a challenge for DFT to investigate correctly the modification of their magnetic properties when contacting a coinage metal surface or/and interacting with classical ligands acting as solvent species.

Molecule-by-Molecule Assembly of Chiral Surfaces
Dexter Rasonbe (supervisor: Ras Raval)
University of Liverpool, UK

Chiral or ‘handed’ surfaces are increasingly being implicated in major advances in nanoscience e.g. smart sensors that can discriminate between mirror-image molecules,  ultra-selective catalysts that promote the creation of just single-handed products, non-linear optical materials and even as potential environments that could have led to the evolution of homochiral living forms on earth! This project will investigate how to create chiral surfaces in which every molecule is organised in the correct position to yield a perfect chiral pattern at a surface. The research will involve using sophisticated surface science methods to assemble chiral surfaces in ultra-high vacuum (UHV), and then probing them using vibrational and electronic spectroscopic methods and scanning tunnelling microscopy (STM).

Promoting the inelastic mode of the STM to a routine use : a DFT-based approach
Shiri Burema (supervisor: Marie-Laure Bocquet)
ENS Lyon, France

If the STM has revolutionized the approach of the imaging at the molecular scale, this technique often remains ambiguous to characterize finely molecules. That is why an important experimental effort was realized during the last years to develop new techniques of spectroscopy on the basis of the STM. In this context the IETS (Inelastic Electron Tunneling Spectroscopy) developed by W. Ho (UC Irvine) has successfully obtained a specific signature of an adsorbed molecule. However the associated phenomena remain complex to interpret without the aid of dedicated simulations.

With the aid of DFT-based IETS simulations, the project will investigate the evolution of the inelastic answer of a family of aromatic molecules such as monosubstituted benzene and phenyl on a metal surface, in order to develop unified rules for facile interpretation of IETS spectra. The ultimate goal is to propose a definitive understanding of the rules of selection.
The successful candidate for this PhD position should have a strong background in Physics, Chemistry, Nanotechnology and current Computational Methods.  He or she should have a strong interest in working with computers and develop some skills in informatics.

On-surface synthesis of functional molecular nanostructures
Sundar Raja Vadapoo (supervisor: Trolle Linderoth)
Aarhus, Denmark

Molecular nanostructures on surfaces are extremely important for a wide range of existing and emerging application areas within nanotechnology such as surface functionalisation, chemical sensing and electronics. A very exciting recent development is the use of “on-surface synthesis” to chemically react molecular building blocks adsorbed on surfaces to form covalently interlinked and highly stable molecular constructions, such as porous 2D polymers, with novel properties. The project will explore fundamental questions and new possibilities within this rapidly developing field, primarily using the technique of Scanning Tunneling Microscopy (STM) which offers unique opportunities for investigating how complex organic molecules bind and organize on surfaces under extremely clean and well-controlled vacuum conditions.