Nickel-based catalysts in aqueous alkaline media are low-cost electrode materials for electrolytic hydrogen generation, a renewable method of producing fuel and industrial feedstock. However, further work is necessary to develop inexpensive electro-catalyst materials with high activity and long-term stability. This thesis employs spectroscopic and electrochemical methods to directly address specific research problems for the development of improved materials and devices with commercial or industrial value. The first chapter reviews the applications of nickel electrodes; the structures of nickel, nickel hydroxides, and nickel hydrides; and techniques for measuring the electrochemically active surface area (AECSA) of nickel. In the second chapter, electrochemically precipitated nickel hydroxide materials are fully characterized by Raman spectroscopy, Fourier-transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). This work unifies and simplifies the large body of literature on the topic by considering two fundamental phases, α- and β-Ni(OH)2, and various types and extents of structural disorder. The third chapter examines and demonstrates the potential applications of in situ Raman spectroscopy by monitoring the spontaneous ageing of α-Ni(OH)2 to β-Ni(OH)2 in pure water at room temperature. The fourth chapter considers the longstanding problem of electrode deactivation, the gradual decrease in nickel electro-catalyst activity during prolonged hydrogen production. Voltammetric and XRD evidence demonstrates that hydrogen atoms can incorporate into the electrode material and cause structural disorder or the formation of α-NiHx and β-NiHx at the surface. The voltammetric formation of NiOx, α-Ni(OH)2, β-Ni(OH)2, and β-NiOOH surface species are examined by electrochemical and XPS measurements. The fifth chapter of this thesis presents a new method to measure the AECSA by adsorption of oxalate to the (001) surface of the surface Ni(OH)2, as evidenced by voltammetric and attenuated total reflectance (ATR) FT-IR spectroscopy measurements. The adsorbed oxalate limits the surface hydroxide to a single layer. The surface NiOOH/Ni(OH)2 reduction peak during the reverse scan may be used to accurately and precisely measure the AECSA. The error of this method is estimated at < 10 %.

It is increasingly important to identify the nature of the interfacial water in biology in order to explain how biological functions and systems work. It is not simply a matter of which biomolecules are present in a cell, but also of how these biomolecules interact with one another. This body of work uses neutron scattering techniques to explain the nature of the vibrational dynamics of water interacting with biomolecules and systems that mimic the biological molecular crowding environment of a cell. Recent work in science has seen the synthesis of periodic mesoporous organosilicas with organic groups attached. In the first paper in this thesis, the use of one of these materials is highlighted to look at confined water, equivalent to the water found in a crowded cellular environment. Here it is shown that the properties of the water within the pores and water molecules around the surface were shown to be different and then identified as interfacial and bulk water respectively. In order to develop the investigation of interfacial water with biological matter, it seemed appropriate to start with the most basic molecules, amino acids. The second paper presents a complete survey of the 20 biologically important amino acids using one of the world's highest resolution neutron scattering spectrometer (TOSCA at ISIS, Rutherford Appleton Laboratory). Computer simulation of the experimental work through molecular dynamics, allows many vibrational modes to be assigned for the first time and correlated with the broader vibrational peaks previously observed for proteins. Comparison of the dry states with the hydrated states of amino acids, gives some insight into the sites within the amino acid side chains where water molecules are likely to bind. For serine this is the hydroxyl group in the side chain. The third paper focuses on IINS data of serine in more detail and discusses several low energy vibrational modes that have been assigned and for the first time, shows how the presence of water molecules changes the dynamic behaviour of librational and torsional modes differently. The combination of these studies allows a clearer picture of how water in biology interacts with biomolecules and of the importance of water to our existence.

- 4 - Abstrakt The aim of this diploma thesis was to determine the possibility of identifying the protein and lipid additives, such as blood, gelatine, curd, lard and eggs, in the model samples of lime based mortars using Raman spectroscopy and gas chromatography- mass spectrometry. It was proved that the method of Raman spectroscopy can determine the presence of organic additives in the order of one weight percent. The gas chromatography enables to detect lipid additives from the order of hundredths weight percent. Unambiguous resolution of protein additives can be done in the samples with the concentrations up to the order of one weight percent of the additives.

Title: Molecular crystals for NLO applications - compounds of 1H-pyrazole-carboxamidine Author: Bc. Soňa Kohúteková Department: Department of Inorganic Chemistry Supervisor: prof. RNDr. Ivan Němec, Ph.D. Abstract: The aim of this diploma thesis is preparation and characterisation of novel compounds of 1H-pyrazole-carboxamidine in consideration of their potential application in the field of nonlinear optics. This thesis is focused on preparation of crystalline salts or adducts combining 1H-pyrazole-carboxamidine with selected inorganic and organic acids. Prepared materials were characterised mainly by the means of vibrational spectroscopy and X-ray diffraction analysis. Quantum-chemical calculations were used for a prediction of nonlinear optical properties as well as for interpretation of measured vibrational spectra. Four different approaches of calculations were used for an optimisation of computing time together with accuracy of the fit of calculated and measured spectra. Finally, measurements of second harmonic generation efficiency of two powder samples with non-centrosymmetric crystal structures were performed. Key words: NLO, vibrational spectroscopy, crystal structure, quantum-chemical calculations

<p>Open questions remain on the influence of various conditions and ion behavior on the hydration-shell of oily molecules. My research uses Raman spectroscopy and Raman multivariate curve resolution to study the hydration-shell of oily molecules as tools to help answer some of these open questions.</p><p>More specifically, I present results on the effect of molecular crowding on the structure of water around various oily molecules, and report the effect of molecular crowding on hydrophobic crossover. These results are important, as crowding has the potential to influence several fields, such as biology and environmental sciences. This work shows that increasing molecular concentration results in oil-oil crowding, decreases the tetrahedrality of the water structure around the oily molecules, and subsequently, the crossover temperature.</p><p>In addition to studying the hydration-shell under crowded conditions, I also present work on ion affiliation for the hydration-shell of an oily molecule. Ion affiliation for oil/water interfaces has been an ongoing topic of research since the Hoffmeister experiments because of their effect on biological processes. This study focuses on hydroxide and its affiliation for tert-butyl alcohol in comparison to other electrolytes. These results show iodide is less repelled by the oil/water interface in comparison to hydroxide.</p><p>Finally, I present findings on the influence of hydrogen peroxide in comparison to other small molecules on the water structure of an oily molecule. Hydrogen peroxide has been shown to reach supercooled temperatures, which may be useful in future studies of liquid phase transitions or studies on solute behavior at supercooled conditions. It is found that hydrogen peroxide does not significantly influence the water structure around tert-butyl alcohol, while other small molecules display significant water structure changes.</p><p>All these projects aim to contribute results to heated debates, as well as share information for future experiments.</p>

We report infrared photodissociation (IRPD) spectra for the D2-tagged titanium oxide cluster anions (TiO2)−n with n = 3–8 in the spectral region from 450 to 1200 cm−1. The IRPD spectra are interpreted with the aid of harmonic spectra from BP86/6-311+G* density functional theory calculations of energetically low-lying isomers. We conclusively assign the IRPD spectra of the n = 3 and n = 6 clusters to global minimum energy structures with Cs and C2 symmetry, respectively. The vibrational spectra of the n = 4 and n = 7 clusters can be attributed to contributions of at most two low-lying structures. While our calculations indicate that the n = 5 and n = 8 clusters have many more low-lying isomers than the other clusters, the dominant contributions to their spectra can be assigned to the lowest energy structures. Through comparison between the calculated and experimental spectra, we can draw conclusions about the size-dependent evolution of the properties of (TiO2)−n clusters, and on their potential utility as model systems for catalysis on a bulk TiO2 surface.

No description available.

Blood is considered one of the most important types of forensic evidence found at a crime scene. The use of surface-enhanced Raman spectroscopy (SERS) provides a potentially non-destructive and highly sensitive technique for the confirmation of blood and this method can be applied using a portable Raman device with quick sample preparation and processing. Crime scenes are inherently complex and the impact of SERS analysis provides easy use and practical application for in-field sample analysis. SERS is one of the few confirmatory techniques employed for the identification of blood at a crime scene or in the forensic laboratory. This method is able to distinguish between blood and other body fluids by collecting a SERS spectrum from a sample placed on a surface that has been embedded with gold nanoparticles (AuNPs). The AuNPs create an electric field surface enhancement that produces an intense molecular vibrational signal, leading to a SERS enhancement. The SERS enhancement allowed for sensitive blood detection at dilutions greater than 1:10,000. A stain transfer method to the SERS substrate was optimized by extracting dried bloodstains with water, saline, and various acid solutions. Fifty percent aqueous acetic acid solutions was found to be the most efficient in retaining the blood components and releasing the hemoglobin component of blood for detection. The SERS spectrum of blood is a robust signature of hemoglobin that does not significantly change between donors nor over time. Characteristic peaks for the identification of blood are 754, 1513, and 1543 wavenumbers (cm-1), attributed to a pyrrole ring breathing mode (15) and two Cβ-Cβ stretches (11, 38), respectively. These key SERS peaks, high sensitivity, and signal enhancement are favorable when compared to normal Raman spectroscopy. A quick and easy-to-use procedure for on-site sample analysis for the detection of blood on different substrates was developed and applied on a portable Raman device. Various nonporous and porous substrates including glass, ceramic tile, cotton, denim, fleece, nylon, acetate, wool, polyester, wood, and coated wood yielded strong results for identification of bloodstains. In addition, different commercial and in-house SERS substrates were tested to determine effectiveness for the detection and identification of blood. SERS identification of blood for forensic work is a potentially non-destructive and portable tool that can be applied for quick and easy examination of evidence at a crime scene. The high sensitivity and selectivity of SERS provides a robust spectroscopic signature that aids in the confirmation of blood, even when it is not visible to the naked eye. It is a more favorable method when compared to current presumptive and confirmatory tests for blood and can be applied to stains on different SERS substrates and a variety sample surfaces for universal testing.

No description available.

Die Struktur und Dynamik von Biomolekülen wird durch ein komplexes Wechselspiel mit Ionen und Wassermolekülen der Hydratationshülle beeinflusst. Die Wechselwirkungen sind kaum verstanden, zum Teil weil es an experimentellen molekularen Sonden mangelt. Lokale Schwingungen des RNA-Rückgrats bieten solch nicht-invasive Sonden, empfindlich gegenüber den ersten Schichten der RNA-Solvatationshülle. Die Empfindlichkeit rührt von elektrischen Feldern auf der biomolekularen Oberfläche. Diese Dissertation nutzt die Sensitivität aus, um mit Femtosekunden-2D-IR-Spektroskopie der asymmetrischen Phosphatstreckschwingung die Rolle positiv geladener Ionen, insbesondere Magnesium, Mg2+, zu untersuchen, die negativ geladene Phosphatgruppen des Rückgrats kompensieren. Erste Experimente an Dimethylphosphat, zusammen mit theoretischen Berechnungen, zeigen eine Blauverschiebung der Phosphatmode aufgrund der Bildung von Kontaktionenpaaren. Kurze Abstände zwischen Mg2+ und der Phosphatgruppe führen zu repulsiven Austauschwechselwirkungen, die die Potentialfläche der Schwingung stören. Bei Doppelstrang-RNA zeigt sich eine starke Abhängigkeit der Phosphatschwingung von lokalen Wasserstrukturen. Frequenzverschiebungen durch den Starkeffekt führen zu drei Schwingungsbanden, die unterschiedliche lokale Geometrien widerspiegeln. Elektrische Felder von solvatisierenden Wassermolekülen beeinflussen dabei das Bindungspotential. Abschließend erlaubt es die Blauverschiebung der Phosphatmode, die Bildung von Mg2+/Phosphat Kontaktionenpaaren in Transfer-RNA quantitativ zu verfolgen. Es wird gezeigt, dass diese die Tertiärstruktur der tRNA stabilisieren, indem sie die Coulombabstoßung zwischen negativ geladenen Phosphatgruppen kompensieren, besonders in kompakten Regionen. Die Dissertation demonstriert das Potential zeitaufgelöster Schwingungsspektroskopie, kombiniert mit theoretischen Beschreibungen auf molekularer Ebene, um die komplexen Interaktionen biomolekularer Solvatationsumgebungen zu erforschen. / The structure and dynamics of biomolecules are influenced by a complex interplay with ions and water molecules in the local hydration shell. The underlying interactions are poorly understood, partly because of a lack of experimental probes that can access the molecular scale. Local vibrations of the RNA backbone provide non-invasive probes sensitive to the first hydration layers of the RNA solvation shell via the imposed electric field on the biomolecular surface. This thesis exploits this sensitivity in femtosecond 2D-IR spectroscopy experiments on the asymmetric phosphate stretch vibration to investigate the role of positively charged ions, particularly the magnesium cation Mg2+, in counteracting the negatively charged phosphate backbone. Initial experiments with the model system dimethyl phosphate in combination with theoretical calculations report a frequency blue-shift due to the formation of contact ion pairs. Short distances between Mg2+ and phosphate lead to exchange repulsion interactions that perturb the vibrational potential energy surface. In double helical RNA, a strong dependence of the phosphate mode on the local hydration structure of the phosphate group is found. Three distinct vibrational peaks reflect different hydration geometries as a result of vibrational Stark shifts. Responsible for the frequency shifts are electric fields from solvating water molecules. Ultimately, the blue-shift of the phosphate mode allows to quantitatively follow the formation of Mg2+-phosphate contact pairs in transfer RNA systems. It is shown that these configurations stabilize the tertiary structure of tRNA molecules by efficiently compensating the Coulomb repulsion from negatively charged phosphate groups, particularly in highly congested regions. The thesis demonstrates the potential of time-resolved vibrational spectroscopy combined with theoretical descriptions on the molecular level to probe the complex interactions of biomolecular solvation environments.