Hydration of an azobenzene derivate

Solute-solvent interactions play an important role in chemistry. The course of a chemical reaction may be altered completely, by changing the solvent. The most abundant solvent on our planet is water. Therefore, it is of the utmost significance to understand the interactions between water and the molecules it solvates.

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Properties and photodissociation of diazocarbene precursors

Carbenes are interesting compounds for organic and inorganic chemists because of their unique reactivity. They may exist in a singlet or triplet state depending on their molecular composition and structure. Smart choice of these two parameters allows reducing the energetic gap between singlet and triplet state. Matrix isolation experiments showed that an appropriate stimulus (e.g. light) is then able to switch the carbene between the two states [1]. We will investigate this behavior with low temperature scanning tunneling microscopy on the single molecule scale.

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Inelastic electron tunneling spectroscopy at solvent related structures

Solvation is a main mechanism for chemical processes, as it determines synthesis and catalytic reactions and is a cutting edge in modern physical chemistry.
To understand solvation on a single molecules basis we use a bottom up approach. In this approach we add single water molecules to adsorbed species on a surface.

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Characterization of the adsorption geometry of halogenobenzene derivatives on metal surfaces by FTIR spectroscopy

To understand the mechanisms of heterogeneous catalysis in detail, the adsorption of organic molecules on metal surfaces is investigated. A well-established method for this system is the Fourier-transform Infrared spectroscopy, in which the absorption of infrared light induces vibrations of the adsorbed molecules.

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Influence of ions and their solvation on the structure of water on metal surfaces

To understand electrochemical processes close to solid-liquid interfaces, it is necessary to investigate the influence of ions and their solvation on the structure of water on metal surfaces. The results can help to understand the process of solvation close to electrodes and, thus, be important for electrocatalytic applications. However, up to now only a few experiments can be found in literature describing solvation on an atomic scale.

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Interaction of Porphyrins with Pre-structured GaN at Room Temperature: Multi STM Study

Gallium Nitride (GaN) is a III/IV group, large bandgap semiconductor. Its unique properties, such as high-thermal conductivity, mechanical stability, and, mainly direct bandgap of 3.4 eV, makes GaN an important material for numerous applications ranging from light-emitting diodes (LEDs), high-power electronics, and high-temperature operating devices to photocatalysis.

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Looking deep into Water

The low-temperature STM/AFM is a combination of an Atomic Force Microscope and a Scanning Tunneling Microscope. The combination of these two powerful scanning probe techniques with subatomic resolution allows us to observe the electronic and the atomic structure of the surface at cryogenic temperatures and manipulate single molecules and atoms.

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Structure formation in heteroepitaxial systems: Co on Ag/Cu/Au

In recent years, thousands of applications have been designed by using the invention of new materials. With such kinds of new materials, human life has become more modern, more convenient, and more effective. Therefore, the more we know about material structure, mobility of atoms, adatoms, and vacancies, the more detail we learn about the characteristics of materials.

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Investigation of the water gas shift reaction by spatially and time resolved pump-probe experiments

The aim of this work is the setup of a pump-probe experiment, combining the high time resolution (fs = 10-15 s) of a laser with the high spatial resolution (100 pm = 10 10 m) of a scanning tunneling microscope (STM). Pump-probe experiments use ultra-short laser pulses to excite the sample in a first step. After a certain delay time, another laser pulse is used to transfer the sample to another excited state. In our case, the two resulting excited states are measured using the STM at temperatures as low as 5 K. The excitation process is tracked in real time by varying the time delay of the laser pulses.

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Combination of a fs-laser with a STM

The aim of this project is the reassembling and implementing of a low-temperature STM with a fs-laser system. Both methods were used successfully for decades. The combination of both techniques enables unique insights in the behavior of single atoms and molecules.

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Diffusion of water on insulating surfaces

Understanding the basic mechanisms of surface processes is of technological importance. Among others, the solvation properties of water – the most commonly used solvent – is of high interest. The surface processes on insulators show relevance in catalysis, electronic switches or nano technology.

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Interaction of water molecules with different molecular adsorption on metal surfaces studied by fast STM

The investigation of molecular adsorbates on metal surfaces and their physio-chemical reactions is of great interest due to their important applications in different fields such as fuel cells, semiconductor industry, corrosion science, environmental chemistry, and catalysis. Insight into molecular interactions with water is a principle step to understand the chemical process and to develop the wetting characteristics of the materials.

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