As the field of organocatalysis is growing, it is becoming more important to understand the specific modes of action of these new organic catalysts. Quantum chemistry, in particular density functional theory, has proven very powerful in exploring reaction mechanisms as well as selectivities in organocatalytic reactions, and is the tool used in this thesis. Different reaction mechanisms of several organocatalytic reactions have been examined, and we have been able to exclude various reaction pathways based on the calculated reaction barriers. The origins of stereoselection in a number of reactions have been rationalized. The computational method has generally reproduced the experimental stereoselectivities satisfactorily. The amino acid-catalyzed aldol reaction has previously been established to go through an enamine intermediate. In the first study of this thesis the understanding of this kind of reactions has been expanded to the dipeptide-catalyzed aldol reaction. The factors governing the enantioselection have been studied, showing how the chirality of the amino acids controls the conformation of the transition state, thereby determining the configuration of the product. In the cinchona thiourea-catalyzed Henry reaction two reaction modes regarding substrate binding to the two sites of the catalyst have been investigated, showing the optimal arrangement for this reaction. This enabled the rationalization of the observed stereoselectivity. The hydrophosphination of α,β-unsaturated aldehydes was studied. The bulky substituent of the chiral prolinol-derived catalyst was shown to effectively shield one face of the reactive iminium intermediate, thereby inducing the stereoselectivity. The transfer hydrogenation of imines using Hantzsch esters as hydride source and axially chiral phosphoric acid catalyst has also been explored. A reaction mode where both the Hantzsch ester and the protonated imine are hydrogen bonded to the phosphoric acid is demonstrated to be the preferred mode of action. The different arrangements leading to the two enantiomers of the product are evaluated for several cases, including the hydride transfer step in the reductive amination of α-branched aldehydes via dynamic kinetic resolution. Finally, the intramolecular aldol reaction of ketoaldehydes catalyzed by guanidinebased triazabicyclodecene (TBD) has been studied. Different mechanistic proposals have been assessed computationally, showing that the favoured reaction pathway is catalyzed by proton shuttling. The ability of a range of guanidines to catalyze this reaction has been investigated. The calculated reaction barriers reproduced the experimental reactivities quite well. / QC 20100719

The work described in this thesis concerns development, synthesis and characterisation of new molecular compounds and materials based on the carbon allotropes fullerene (C60) and graphene. A stepwise strategy to a symmetric ferrocene-linked dumbbell of fulleropyrrolidines was developed. The versatility of this approach was demonstrated in the synthesis of a non-symmetric fulleropyrrolidine-ferrocene-tryptophan triad. A new tethered bis-aldehyde, capable of regiospecific bis-pyrrolidination of a C60-fullerene in predominantly trans fashion, was designed, synthesised and reacted with glycine and C60 to yield the desired N-unfunctionalised bis(pyrrolidine)fullerene. A catenane dimer composed of two bis(pyrrolidine)fullerenes was obtained as a minor co-product. From the synthesis of the N-methyl analogue, the catenane dimer could be separated from the monomeric main product and fully characterised by NMR spectroscopy. Working towards organometallic fullerene-based molecular wires, the N-unfunctionalised bis(pyrrolidine)fullerene was coupled to an activated carboxyferrocene-fullerene fragment by amide links to yield a ferrocene-linked fullerene trimer, as indicated by mass spectrometry from reactions carried out at small scale A small library of conjugated diarylacetylene linkers, to be coupled to C60 via metal-mediated hydroarylation, was developed. Selected linker precursors were prepared and characterised, and the hydroarylation has been adapted using simple arylboronic acids. Few-layer graphene was prepared and dip-deposited from suspension onto a piezoelectric polymer substrate. Spontaneous side-selective deposition was observed and, from the perspective of non-covalent interaction, rationalised as being driven by the inbuilt polarization of the polymer. Aiming for selectively edge-oxidized graphene, a number of graphitic materials were treated with a combination of ozone and hydrogen peroxide under sonication. This mild, metal-free procedure led to edge-oxidation and exfoliation with very simple isolation of clean materials indicated by microscopy, spectroscopy, and thermogravimetric analysis.

The aim of the project was to synthesize α1,2-linked and α1,6-linked dimannosides linked through either an oxygen-atom or a sulphur-atom, and subsequently test the binding properties of the dimannosides to lectins with known specificity towards mannose-containing glycans. Thedimannosides were prepared by a glycosylation reaction using selectively protected monosaccharides containing a thiol or alcohol nucleophilic glycosyl acceptor and a series of different glycosyl donors. The synthetic routes to the different building blocks were designed to efficiently make use of common intermediate compounds to streamline the synthesis. The glycosyl acceptors used forthe synthesis of α1,2-linked as well as α1,6-linked dimannosides were synthesized in few steps and diversified only in the last steps of the synthesis. The glycosyl donors used in the study were synthesized from commercially available starting material in a straightforward and convenientsynthesis in 7 to 8 steps.

Syftet med arbetet var att undersöka effekten av olika kvalitéer av shea-stearin och palmolja med avseende på solid fat content (SFC)-värdet efter att fettet hade genomgått en simulering av en deodoriseringsprocess. Utöver att undersöka olika kvalitéer testades även effekten av två olika grundrecept med stora andelar av shea-stearin och palmolja. Recepten bestod av en mindre andel shea-stearin och resterande var palmolja (recept A) samt högre andel shea-stearin med resterande palmolja (recept B). Andelen diglycerider för samtliga prover studerades för att undersöka dess effekt på SFC-värdet. Metoderna som användes för försöken var en simulator som skulle efterlikna en deodorisör samt så användes externa NMR och HPLC-analyser för att få ut solid fat content respektive andelen diglycerider för proverna. Resultaten visade att andelen av shea-stearin och palmolja i en lösning har en tydlig påverkan på SFC-värdet då skillnader i SFC-värdena observerades för samtliga prov. Beroende på receptet kunde även skillnader ses före och efter deodoriseringen där receptet med störst andel shea-stearin gav störst skillnad i SFC-värden. Andelen diglycerider observerades ha en tydlig omvänd korrelation med både SFC-värdet och kvalitén av en olja. Vid tillsättning av god kvalité med lägre andel diglycerider observerades det att SFC-värdet ökade. Slutsatsen är att receptet har störst påverkan för SFC-värdet men även andelen av god kvalité jämfört med sämre kvalité sågs ha en effekt. Även om tydliga mönster observerades genom att undersöka SFC-kurvor utifrån av andelen diglycerider och dess effekt på SFC-värdet i en fettlösning, så går det inte att fastställa orsaken till detta och mekanismerna utan ytterligare undersökning.

In recent years, there has been a rise in the use of New Psychoactive Substances (NPS) that mimic the effects of controlled drugs and licensed medicines, which have become a significant public health concern globally. Synthetic cannabinoids, a rapidly expanding category of NPS, with much higher potency and binding affinity to the cannabinoid receptors than ∆9-tetrahydrocannabinol (THC), have led to serious psychiatric complications and other adverse effects. This project aims to synthesize and analyze four potential metabolites of a synthetic cannabinoid, ADB-5´Br-BUTINACA, to determine if the synthesized metabolites correspond to those produced in human hepatocytes. The metabolites were synthesized by alkylation, amide coupling, and hydrolysis/TFA treatment and analyzed using high-performance liquid chromatography-mass spectrometry (HPLC-MS) and nuclear magnetic resonance (NMR). The reaction strategy combined all three steps into a single process, making it significantly easier to carry out and not requiring much expertise. The results suggest that the synthetic approach used in this project was successful in generating the desired potential metabolites, with overall yields varying from 27.5 % to 57.6 % and high purities ranging from 95.6 % to 99.3 %. However, the overall yields were lower than expected due to product loss during the transfer of the solution mixture, the possibility of side reactions, and incomplete conversion. Further optimization of reaction conditions may be necessary to improve the yield of the synthesized metabolites.

Beer is a fermented alcoholic beverage that spans back to over 5000 years years ago and is consumed all over the world. Beer is usually made from malted barley but it can also be made from different cereals and starches. Beer contains both saturated and unsaturated fatty acids (FA) which are derived from the malt that is used. Unsaturated fatty acids (FA) such as linoleic and linolenic acid are sensitive to oxidation which can affect foam, smell and taste of a beer. The purpose of this study was to extract and analyse FA profile of three different types of beer, Bryggmästaren Bästa Ekologiska, 5,2:an and Premium Gold to assess the durability of these types of beer.  Beer, fermented solution, malt and wort was provided by Åbro Bryggeri. Lipid extraction was performed on the samples, lipids were extracted with soxtec for malted product and liquid-liquid extraction for beer, fermented solution and wort. The lipids were analysed with Gas-Chromatography Flame Ion Detector.  The malted products contained unsaturated FA’s where linoleic acid was the dominating FA while the beers, fermented solutions and worts contained both unsaturated FAs and saturated FAs. The unsaturated FA were erucic acid while the saturated FAs were lauric acid, myristic acid and palmitic acid. The amount of FA’s detected in the beer was extremely low which is due to the method used as some fat might have been lost out during the liquid-liquid extraction or during an evaporation step due to a leakage in the selected rotary evaporation system. The conclusion of this study was that although fatty acids were present in malt and liquids from the brewing process, the amount was too low to cause risk of either an altered taste of the beer or increased risk of oxidation of unsaturated FAs. However, due to a limitation of data from extracted- and analysed samples, this reduces the outcome of this work and a quantitative study is needed in order to determine more exact FA profiles from the analysed samples.

Elever i gymnasieskolan visar svårigheter att skapa sig äkta förståelse för ämnet kemi. Detta kan bero på en omfattande mängd material men också att kemiämnet traditionellt är uppdelat i separata kategorier. Elever uppvisar inte förmåga att se helheten och kopplingen mellan dessa delar.Arbetet diskuterar möjligheten för ämnesläraren att utgå från så kallade ”stora idéer” och sedan avancera innehållet enligt en bestämd ordning. Detta kan vara ett sätt att skapa helhetsbild, bättre överblick och därigenom djupare förståelse av kemin som ämne.Genom lärarintervjuer undersöks olika lärares syn på organisk kemi i undervisningen och om specifika moment finns inom kursen kemi 1 där fler exempel på den organiska kemins grunder kan introduceras för gymnasieelever.Stora idéer som sammanfattar gymnasiekemins grundkurs (kemi1) samt organisk kemi (del av kemi 2) presenteras i arbetet. Dessutom föreslås fyra olika moment i kemi 1 där fler exempel på grunder i organisk kemi kan tas upp för att förbereda elever för organisk kemi utan att betunga kunskapsområdet med mer teori.

En vanlig källa till kontakallergiskt eksem är sensibiliserande (allergiframkallande) kemikalier som finns i hårfärger. Permanenta hårfärger innehåller kraftiga allergener, men det saknas kartläggande forskning på toningar. För att ta reda på vilka allergener som ingår i toningar behöver dagens utbud kartläggas. Detta projekt har skett i Stockholm och innehållet i sex olika märken har kartlagts. Toningar och permanenta hårfärger skiljer sig åt genom att permanenta hårfärger polymeriseras i håret genom oxidation med väteperoxid. Toningar innehåller kromofora ämnen som fäster i håret, antingen genom diffusion eller adsorption. Totalt kunde tio kromofora ämnen med kända sensibiliserande egenskaper hittas i toningarna varav en möjlig cancerogen. I varje produkt fanns i snitt 0,4–2,4, och som mest tre, kända sensibiliserande kromofora ämnen. Hårfärger utan sensibiliserande färgämnen kunde hittas i alla kulörer utom svart och brun. Även sensibiliserande parfymämnen och konserveringsmedel kunde påvisas. Eftersom det finns hårfärger i de flesta kulörer utan sensibiliserande färgämnen bör dessa ämnen fasas ut.

No description available.

This thesis is divided into four parts with organic chromophores for dye sensitized solar cells as the common feature and an introduction with general concepts of the dye sensitized solar cells. The first part of the thesis describes the development of an efficient organic chromophore for dye sensitized solar cells. The chromophore consists of a triphenylamine moiety as an electron donor, a conjugated linker with a thiophene moiety and cyanoacrylic acid as an electron acceptor and anchoring group. During this work a strategy to obtain an efficient sensitizer was developed. Alternating the donor, linker or acceptor moieties independently, would give us the tool to tune the HOMO and LUMO energy levels of the chromophores. The following parts of this thesis regard this development strategy. The second part describes the contributions to the HOMO and LUMO energy levels when alternating the linker moiety. By varying the linker the HOMO and LUMO energy levels was indeed shifted. Unexpected effects of the solar cell performances when increasing the linker length were revealed, however. The third part describes the investigation of an alternative acceptor group, rhodanine-3-acetic acid, in combination with different linker lengths. The HOMO and LUMO energy level tuning was once again successfully shifted. The poor electronic coupling of the acceptor group to the semiconductor surface proved to be a problem for the overall efficiency of the solar cell, however. The fourth part describes the contributions from different donor groups to the HOMO and LUMO energy levels and has so far been the most successful in terms of reaching high efficiencies in the solar cell. A top overall efficiency of 7.1 % was achieved. / QC 20101108