<p>In discussions of heterogeneous catalysis and other surface-related phenomena, the dynamical properties of the catalytic material are often neglected, even at elevated temperatures. An example is the three-way catalyst (TWC), used for treatment of exhaust gases from combustion engines operating at several hundred degrees Celsius. In the TWC, reduced ceria (CeO_2-x) is one of the key components, where it functions as an oxygen buffer, storing and releasing oxygen to provide optimal conditions for the catalytic conversion of the pollutants. In this process it is evident that dynamics plays a crucial role, not only ionic vibrations, but also oxygen diffusion.</p><p>In this thesis, the structure and dynamics of several ionic crystalline compounds and their surfaces have been studied by means of Molecular dynamics (MD) simulations and Lattice dynamics (LD) calculations. The main focus lies on CeO_2-x, but also CeO₂, MgO and CaF₂ have been investigated.</p><p>The presence of oxygen vacancies in ceria is found to lead to significant distortions of the oxygen framework around the defect (but not of the cerium framework). As a consequence, a new O-O distance emerges, as well as a significantly broadened Ce-O distance distribution.</p><p>The presence of oxygen vacancies in ceria also leads to increased dynamics. The oxygen self-diffusion in reduced ceria was calculated from MD simulations in the temperature range 800-2000 K, and was found to follow an Arrhenius behaviour with a vacancy mechanism along the crystallographic <100> directions only.</p><p>The cation and anion vibrational surface dynamics were investigated for MgO (001) using DFT-LD and for CaF₂ (111) in a combined LEED and MD study. Specific surface modes were found for MgO and increased surface dynamics was found both experimentally and theoretically for CaF₂, which is isostructural with CeO₂.</p><p>Many methodological aspects of modeling dynamics in ionic solids are also covered in this thesis. In many cases, the representation of the model system (slab thickness, simulation box-size and the choice of ensemble) was found to have a significant influence on the results.</p>

<p>A novel strategy for synthesising segmented poly(urethane urea) (PUU) without using a chain extender but nevertheless with the opportunity to vary the hard segment content has been developed. The strategy is based on amine formation from isocyanate upon reaction with water. By adding a dissolved soft segment to an excess of diisocyanate followed by the addition of water in the gas phase, amines are formed <i>in situ</i>. Urea linkages are then formed when these amines react with the excess of isocyanate groups. The gas phase addition facilitates addition in a slow and continuous manner. The hard segment content can easily altered by varying the diisocyanate/soft segment ratio. Even though the strategy is shown to be applicable to different diisocyanates, the focus has been on the potentially biodegradable methyl-2,6-diisocyanatehexanoate (LDI) and 1.4-butanediisocyanate (BDI) and various well known biodegradable polyesters and polycarbonates. </p><p>All the synthesised materials exhibited pronounced phase separation and hydrogen bonding within the hard domains. However, a major increase in hydrogen bonding strength was seen when a symmetric diisocyanate was used instead of an asymmetric. Based on FTIR measurements, PUUs with BDI and a polydisperse hard segment can exhibit the same degree of phase separation and hydrogen bonding as the monodisperse product.</p><p>The elastic properties of this new group of PUUs were exceptional with an elongation at break from 1600% to almost 5000% and the elastic modulus could be varied from a few MPa up to a couple of hundreds. </p><p>Hydrolytic degradation was greater in the polyester-based than in the polycarbonate-based PUUs due to the more reactive ester bonds. Low mass loss but a considerable loss in molecular weight was seen in the polyester PUUs. The tensile strength decreased dramatically due to the loss of strain hardening.</p><p>An MTT seeding assay using human fibroblasts and an in vivo biocompatibility study were performed and no signs of cytotoxicity were seen and the inflammatory response was comparable to other inert polymers.</p><p>A biodegradable PUU with properties that can be tailored through an easy synthesis is here presented. </p>

<p>Objectives: To evaluate the long term total imprecision of HbA1c testing within the county of Uppsala in relation to the Swedish analytical goal of coefficient of variation (CV) <3% for HbA1c and to study the cost of an external quality assurance program for point-of-care HbA1c The county uses Bayer DCA 2000™ for point-of care HbA1c testing currently having 23 of these instruments.</p><p>Methods: Method imprecision was assessed by analysis of patient samples performed as split samples during a 3 year period (2002-2004) as part of the quality assurance program for point-of-care HbA1c testing. The samples were first analysed on a Bayer DCA 2000™ and the samples were then sent to the centralised laboratory for reanalysis with an HPLC system (Variant II™, Biorad). The testing was performed approximately 8 times per year with each instrument.</p><p>Results: The median CV between the HPLC method and the point-of-care instruments for each unit was slightly higher than 3%.</p><p>Conclusion: The DCA 2000™ systems have an acceptable imprecision and agreement with the central laboratory. The test results show acceptable agreements within the county regardless where the patient is tested. The cost of the external quality assurance program is calculated to be approximately SEK 1340 (Euro 150) per instrument.</p>

<p>Electrochemical deposition finds applications in the electronics- and protective coating industries. The technique is a versatile tool for the synthesis of alloys and thin films. Knowledge of the fundamental aspects of the electrode processes enables the design of nanostructured materials. In this thesis, electrodeposition processes in solutions containing metal ion complexes were studied and new methods for the preparation of metal/metal-oxide coatings were developed and evaluated. </p><p>Metal/metal oxide coatings were electrodeposited from aqueous solutions containing metal complexes of hydroxycarboxylic acids under reducing conditions. The mass changes of the working electrode were monitored <i>in-situ</i> with the electrochemical quartz crystal microbalance (EQCM) technique and ellipsometry was used to detect the formation of Cu₂O. The coatings were further characterized with XRD, XPS, SEM, TEM, and Raman spectroscopy. Electrochemical methods, including reduction of Sb/Sb₂O₃ in an organic electrolyte, were also used to study the properties of the deposited materials. </p><p>Nanostructured coatings of Cu/Cu₂O were obtained during spontaneous potential or current oscillations in alkaline Cu(II)-citrate solutions. The oscillations were due to local pH variations induced by a subsequent chemical step and comproportionation between Cu and Cu²⁺. Well-defined layers of Cu and Cu₂O could be prepared by a galvanostatic pulsing technique, allowing independently controlled thickness of several hundred nanometers. Coatings, containing Sb and co-deposited, nanograins of Sb₂O_3, with a thickness of up to 200 nm were prepared from poorly buffered Sb(III)-tartrate solutions. Galvanostatic cycling showed that the latter material could be reversibly charged and discharged in a Li-ion battery for more than 50 cycles with a capacity of 660 mAh/g. </p><p>The results show that precipitations of metal oxides can occur due to local pH increases during electrochemical deposition from metal complexes with ligands containing hydroxyl groups. The ability to deposit metal oxides using cathodic deposition relies on a sufficiently slow reduction of the oxide. </p>

<p>This thesis is based on six research publications concerned with (i) study of the molecular structures and dynamics of modified nucleosides; (ii) investigation of the effect of incorporation of modified nucleosides on the structure of DNA; (iii) examination of the effect of the sugar modifications on the pseudo-aromatic properties (p<i>K</i>_a) of the nucleobases; (iv) analysis of the effect of the CH-π interactions on the relative stability of the DNA-RNA hybrid duplexes. The structural stability of the nucleic acids as well as their behavior in molecular recognition is dominated by hydrogen bonding and stacking interactions beside other non-covalent interactions. Naturally occurring nucleosides are found to have some specific functions. Modifications of nucleic acids, followed by studies of the resulting structural, chemical and functional changes, contribute to an understanding of their role in various biochemical processes, such as catalysis or gene silencing. In papers I-III, analysis of the structures of modified thymidine nucleosides with 1′,2′-(oxetane or azetidine) and 2′,4′-(LNA, 2′-amino LNA, ENA, and Aza-ENA) conformationally constrained sugar moieties, and dynamics of the modified nucleosides by NMR, ab initio, and molecular dynamics simulations are discussed. Based on whether the modification leads to 1′,2′- or 2′,4′- constrained sugar moieties, it is found that they fall into two distinct categories characterized by their respective internal dynamics of the glycosidic and backbone torsions as well as by their characteristic <i>NE</i>-type (P = 37° ± 27°, Φ_m = 25° ± 18°) for 1′,2′-constrained nucleosides, and <i>N</i>-type (P = 19° ± 8°, Φ_m = 48° ± 4°) for 2′,4′-constrained systems, respectively. Moreover, each group has different conformational hyperspace accessible. The effect of the incorporation of 1′,2′-oxetane locked thymidine nucleoside on the structure and dynamics of the Dickerson-Drew dodecamer, d(CGCGAATTCGCG)₂, determined by NMR, is discussed in the paper IV. It shows that the incorporation of oxetane locked T into the dodecamer has made local structural deformations and perturbation in base pairing, where the modification is included. The modulations of physico-chemical properties of the nucleobases in nucleotides by the C2′-modification of the sugar (paper V), 5′-phosphate group, and the effect of constrained pentofuranosyl moiety (sugar, paper III) have been studied. CH-π interactions between the methyl group of thymidine and the neighboring aromatic nucleobase are shown to increase the relative stability of the DNA-RNA hybrid duplexes over the isosequential RNA-DNA duplexes or vice versa (paper VI).</p>

<p>Nanoparticles of iron, cobalt and tungsten oxide were synthesised by photolytic laser assisted chemical vapour deposition (LCVD). An excimer laser (operating at 193 nm) was used as an excitation source. The LCVD process, was monitored <i>in situ</i> by optical emission spectroscopy (OES). The synthesised particles were further analysed using transmission electron spectroscopy (TEM), X-ray diffraction (XRD), high resolution scanning electron microscopy (HRSEM), X-ray fluorescence spectroscopy (XRF), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy.</p><p>Iron and cobalt single crystalline nanoparticles were synthesized using ferrocene and cobaltocene precursors. The diameter of the particles could be tailored by the experimental parameters (e.g., partial pressure and laser power) and were in the range 1 - 50 nm in diameter. In both cases, the particles were covered by a carbon shell, typically 7 nm thick. A thin graphitic layer was observed at the interface metal-carbon. Amorphous carbon was deposited on top of the graphitic carbon. Particle temperature, reaching the boiling point of the respective metal, was observed by OES of the thermal emission during the laser-induced particle formation process (and subsequent heating). Both bcc and fcc Fe phases were formed, both hcp and fcc for the Co phases. Size dependent magnetic properties were observed using superconducting quantum interference device (SQUID) measurements, where super-paramagnetic magnetic domains dominated for <i>d</i> < 10 nm. The iron particles were further processed, whereby the amorphous shell was removed by refluxing in nitric acid. In a subsequent step, the graphitic surface was functionalized by attaching an octyl ester, rendering the particles hydrophobic.</p><p>Tungsten oxides were synthesized from combinations of WF₆/H₂/O₂ as precursors. No particles could be deposited if H₂ was removed from the gas-mixture. The as-deposited oxide nanoparticle film was amorphous. A monoclinic WO₃ particle film could be achieved by annealing the amorphous oxide. Above 400°C, the oxide particles increased in size from ca. 20 nm to 60 nm through coalescence. The gas-sensing properties of the tungsten oxide were tested by conductance measurements using H₂S as analyte. The sensitivity of the amorphous oxide nanoparticle film was found to be superior to that of a crystalline oxide nanoparticle film. </p>

<p>Diamond and cubic boron nitride surfaces have extreme properties that can be exploited in novel tribological, electrochemical and electronic applications. Normally insulating diamond surfaces can exhibit high surface conductivities due to hydrogen termination and the nature of the surrounding atmosphere. Successful growth of cubic boron nitride thin films is hindered when harsh synthesis methods are used.</p><p>Three significant surface-related properties are addressed in this thesis using computational methods: (1) the structure, energy stability and reactivity of clean and differently terminated diamond surfaces, (2) the high surface conductivity of diamond, and (3) the adsorption-induced stability, reactivity and reconstruction of the cubic boron nitride (100) surface. Density Functional Theory (DFT) has been used at the GGA level under periodic boundary conditions to simulate the diamond and cubic boron nitride surfaces. </p><p>The diamond surface structures are shown to be insensitive to hydrogen desorption. Oxygen atoms bind in different positions and with different bond strengths. Hydroxyl groups experience both attractive hydrogen bonding and steric repulsions within the adsorbed species. The reconstruction of diamond (111)-1x1 is strongly dependent on the species adsorbed onto the surface. Electron transfer was observed from a diamond surface into a water-based adlayer, yielding a p-type doped surface, depending on the nature of the surface and the adlayer. The cubic boron nitride (100)-1x1 surface was shown to reconstruct into a 2x1 configuration on both the boron- and nitrogen-rich side through the formation of B-B bonds, as well as N–N dimer-induced surface relaxation. Hydrogen stabilized the (100)-1x1 surface, but the partial removal of hydrogen yielded non-reactive dimer formation on the surface. </p>

Stereochemistry plays an important role in nature because biologically important molecules such as amino acids, nucleotides and sugars, only exist in enantiomerically pure forms. Semiochemicals carry messages, between the same species (pheromones) and between different species (allelochemicals). Both pheromones and allelochemicals can be used as environmentally friendly pest management. Many semiochemicals, i.e. behaviour modifying chemicals, consist of pure or well-defined mixtures of stereoisomers, where some of the other stereoisomers can be repellent. It is therefore important to be able to separate them to produce a synthetic pheromone in a mixture that is attractive. Pine sawflies are a family of insects that in some cases can be severe defoliators of conifer trees. Diprion pini, Diprion similis and Neodiprion sertifer are severe pests for these trees and have got the most attention in pine sawfly pheromone studies. The pheromone precursors are stored in the female body as long-chain secondary alcohols, which, when released, are esterified to acetates or propionates. The alcohols are chiral, and normally one of the stereoisomer is the main pheromone component, sometimes possible together with other stereoisomers as essential minor components. Bicyclus is a genus of African butterflies, and especially Bicyclus anynana has become a popular model for the study of life history evolution, morphology, mating choice and genetics. The wing pattern of Bicyclus differs depending on the season, with large eyespots during the rain-season and small or absent spots during the dry season.  Euglossa is one of the genera among the orchid bees in the Neotropics that does not produce its own pheromone. Instead, the males collect fragrances from orchids and other sources and store them in a pocket in their hind legs. Both Bicyclus and Euglossa use semiochemicals similar to pine sawflies, and thus can be analysed by the same methods. Pheromones and other semiochemicals in insects are often present in low amounts in a complex matrix, and purification of the sample before chemical analysis is often required. A common method is gradient elution on a solid phase silica column. Separation of stereoisomers can be achieved either by using a column with a chiral stationary phase (CSP) or with pre-column derivatisation using a column with an achiral stationary phase (ASP) or a combination of both, with mass detection as the dominant detection method. The purpose of this work has been to improve the purification method, find suitable methods to separate the stereoisomers of secondary alcohols, and to apply this on extracts of insects. By selecting the right fractions to collect during gradient elution the purification method was optimised. To reduce plasticizer contamination from ordinary columns, solid phase columns of Teflon or glass were used. For pre-column derivatisation of different chiral alcohols various acid chlorides were tested. For the pine sawfly pheromone precursors enantiopure (2S)-2-acetoxypropionyl chloride was the best choice. To separate some of the stereoisomers achiral 2-naphthoyl chloride was used. For derivatisation of 6,10,14-trimethylpentadecan-2-ol (R)-trans-chrysanthemoyl chloride was the best choice. The derivatised alcohols were separated on different columns, both chiral and non-chiral. Varian FactorFour VF-23ms was chosen as a general-purpose column, the Agilent HP-88 column was the best column with an ASP of those tested, and the Chiraldex B-PA column (CSP) was the only one that could separate all eight stereoisomers of derivatised 3,7-dimethylundecan-2-ol, 3,7-dimethyldodecan-2-ol, and 3,7-dimethyltridecan-2-ol. To determine the stereoisomeric purity of standard solutions used in field experiments and extracts of different species of insects the optimised methods were applied. For extracts from B. anynana, Euglossa and Neodiprion lecontei this work describe the first determination of the stereochemistry of some of their semiochemicals. For the determination of the stereochemistry of chiral semiochemicals the methods for purification and separation presented herein have shown to be of great value. The results will hopefully contribute to a better understanding of the communication among insects, and ultimately to a more environmentally friendly pest control. / Många naturligt förekommande kemiska ämnen finns som två spegelbilder av varandra, ungefär som höger och vänster hand. Dessa kan ha helt olika egenskaper och det är därför viktigt att kunna separera dem. Insekter och andra djur använder olika doftämnen för att kommunicera med varandra, om det är inom samma art kallas de för feromoner. De kan bestå av ett ämne eller en blandning av flera. Dessa doftämnen kan man även använda för att på ett miljövänligt sätt bekämpa skadeinsekter. En fälla med syntetiskt feromon för en viss insekt lockar endast till sig den arten, medan alla andra är opåverkade. Eftersom dessa ämnen ofta finns som spegelbilder där kanske bara den ena är aktiv och den andra rent av frånstötande, måste man kunna separera dem för att framställa ett syntetiskt feromon som är attraktivt. Målet med detta arbete har varit att bestämma feromonet hos olika arter av tallsteklar som kan vara svåra skadedjur på tallskog. De metoder som tagits fram har även tillämpats på några arter av afrikanska fjärilar samt orkidébin från Centralamerika eftersom de använder snarlika doftämnen. Att få fram feromonet från en insekt är lite som att leta efter in nål i en höstack eftersom de ofta bara innehåller några miljarddels gram per individ. Provet behöver först renas, och en del av arbetet i det här projektet har gått ut på att ta fram en lämplig reningsmetod. Huvudfokus har dock varit på att ta fram metoder som kan separera och identifiera det eller de ämnen, och spegelbilder av dessa, som doftämnena består av. När lämpliga metoder tagits fram har extrakt av olika insektsarter analyserats. I några fall är det första gången som deras feromon bestämts i detalj. Resultaten kan förhoppningsvis bidra till en ökad kunskap om insekters sätt att kommunicera, och i slutändan till miljövänligare bekämpning av skadeinsekter.

This work deals with radiochemistry and new approaches to develop novel PET tracers labelled with the radionuclide 11C. Two methods for the synthesis of 11C-labelled acrylamides have been explored. First, [1-11C]-acrylic acid was obtained from a palladium(0)-mediated 11C-carboxylation of acetylene with [11C]carbon monoxide; this could be converted to the corresponding acyl chloride and then combined with benzylamine to form N-benzyl[carbonyl-11C]acrylamide. In the second method, the palladium(0)-mediated carbonylation of vinyl halides with [11C]carbon monoxide was explored. This latter method, yielded labelled acrylamides in a single step with retention of configuration at the C=C double bond, and required less amine compared to the acetylene method. The vinyl halide method was used to synthesize a library of 11C-labelled EGFr-inhibitors in 7-61% decay corrected radiochemical yield via a combinatorial approach. The compounds were designed to target either the active or the inactive form of EGFr, following computational docking studies. The rhodium(I)-mediated carbonylative cross-coupling of an azide and an amine was shown to be a very general reaction and was used to synthesize a library of dual VEGFr-2/PDGFrβ inhibitors that were 11C-labelled at the urea position in 38-78% dc rcy. The angiotensin II AT1 receptor antagonist eprosartan was 11C-labelled at one of the carboxyl groups in one step using a palladium(0)-mediated carboxylation. Autoradiography shows specific binding in rat kidney, lung and adrenal cortex, and organ distribution shows a high accumulation in the intestines, kidneys and liver. Specific binding in frozen sections of human adrenal incidentalomas warrants further investigations of this tracer. Three angiotensin II AT2 ligands were 11C-labelled at the amide group in a palladium(0)-mediated aminocarbonylation in 16-36% dc rcy. One of the compounds was evaluated using in vitro using autoradiography, and in vivo using organ distribution and animal PET. The compound was metabolized fast and excreted via urine. High radioactivity was also found in the liver, meaning that more metabolically stable compounds are desirable for future development.

This thesis describes the development and study of catalysts for redox reactions, which either utilize oxygen or hydrogen peroxide for the purpose of selectively oxidizing organic substrates, or produce oxygen as the necessary byproduct in the production of hydrogen by artificial photosynthesis. The first chapter gives a general introduction about the use of environmentally friendly oxidants in the field of organic synthesis, and about the field of artificial photosynthesis. The second chapter describes a computational study of the mechanism of palladium-catalyzed oxidative carbohydroxylation of allene-substituted conjugated dienes. The proposed mechanism, which was supported by DFT calculations, involves an unusual water attack on a (π-allyl)palladium complex. The third chapter describes a computational study of the oxidation of unfunctionalized hydrocarbons, ethers and alcohols with hydrogen peroxide, catalyzed by methyltrioxorhenium (MTO). The mechanism was found to proceed via rate-limiting hydride abstraction followed by hydroxide transfer in a single concerted, but highly asynchronous, step as shown by intrinsic reaction coordinate (IRC) scans. The fourth chapter describes the use of a new hybrid (hydroquinone-Schiff base)cobalt catalyst as electron transfer mediator (ETM) in the palladium-catalyzed aerobic carbocyclization of enallenes. Covalently linking the two ETMs gave a fivefold rate increase compared to the use of separate components. The fifth chapter describes an improved synthetic route to the (hydroquinone-Schiff base)cobalt catalysts. Preparation of the key intermediate 5-(2,5-hydroxyphenyl)salicylaldehyde was improved by optimization of the key Suzuki coupling and change of protecting groups from methyl ethers to easily cleaved THP groups. The catalysts could thus be prepared in good overall yield from inexpensive starting materials. Finally, the sixth chapter describes the preparation and study of two catalysts for water oxidation, both based on ligands containing imidazole groups, analogous to the histidine residues present in the oxygen evolving complex (OEC) and in many other metalloenzymes. The first, ruthenium-based, catalyst was found to catalyze highly efficient water oxidation induced by visible light. The second catalyst is, to the best of our knowledge, the first homogeneous manganese complex to catalyze light-driven water oxidation. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 5: Accepted. Paper 6: Submitted.</p>