Under min utbildning har jag fått upp ögonen för ämnet kemi och på så sätt uppmärksammat att det inte bedrivs så mycket kemi i dagens förskolor. Det experimeneras en del i förskolan men man benämner det inte med ordet kemi. Det har via TIMSS rapporterats att intresset för kemi minskar stadigt. Utifrån dessa reflektioner har jag skapat ett arbetsmaterial inom kemi för förskolan. Materialet har använts och sedan utvärderats av förskollärare via enkäter.

<p>Syftet med detta arbete är att ge en bild av hur bedömning och betygsättning sker i kemiundervisningen i gymnasiet idag. Utsagor från intervjuade lärare tyder på att det ses som en viktig uppgift, används både i formativt och summativt syfte och tar tid. Ofta väger skriftliga prov, laborationsrapporter samt aktivitet under lektionstid tyngst för betyget, men hänsyn tas till många aspekter och delmoment. Projektarbeten och fördjupningar uppges av en av fem lärare som tungt vägande och bedöms utifrån muntliga redovisningar. Vid bedömningar används nationella målkriterier samt lokala eller personliga kriterier, som utgår från de nationella. De av Skolverket rekommenderade bedömningsmatriserna med både på förhand bestämda kriterier och kvalitetsnivåbeskrivningar används ej och inte heller nämns lokala arbetsplaner. Resultatet visar slutligen att det finns en frustration över betygskriteriernas otydlighet, som anses leda till att lärare gör sinsemellan olika bedömningar.</p> / <p>The focus in this report is assessment practice in chemistry education in upper secondary schools. Statements from interviewed teachers point to that assessment is thought of as an important task, is used in both formative and summative purposes and takes long time. Written exams, lab-reports and activity during lessons often are the most important aspects for the mark, but many factors and other activities are also considered. One of five teachers specified projects, like literature studies, to be of importance for the mark and assessed these based on oral presentations. When assessing, the teachers use national goal-referenced criteria and local or personal criteria, based on the national. The Swedish Board of Education recommends the use of rubrics, with beforehand formulated criteria and quality level descriptions. This is not mentioned as being used and neither are local educational plans. The result shows a frustration over the difficulty to interpret the mark criteria that is considered to result in differences in assessments among teachers.</p>

<p>In this thesis, mechanistic and synthetic studies on transformations of H-phosphonates into DNA analogues containing P-S or P-C bonds are described. </p><p>Configurational stability of dinucleoside H-phosphonates and the stereochemical course of their sulfurisation in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) were investigated. In light of these studies, the reported stereoselective sulfurisation of dinucleoside H-phosphonates and benzoylphosphonates in the presence of DBU was proved to be incorrect.</p><p>Efficient protocols for the synthesis of new nucleotide analogues with non-ionic C-phosphonate internucleotide linkages were developed. The synthesis of dinucleoside 2-pyridylphosphonates was successfully performed by a DBU-promoted reaction of H-phosphonate diesters with <i>N</i>-methoxypyridinium salts. The thio analogues, 2-pyridyl- and 4-pyridyl phosphono<i>thio</i>ate diesters, could be obtained by modifying the reactions developed for their oxo counterparts. Dinucleoside 3-pyridylphosphonates were prepared <i>via</i> a palladium(0)-catalysed cross coupling strategy that could be extended also to the synthesis of nucleotide analogues with metal-complexing properties, <i>i.e</i>. terpyridyl- and bipyridylphosphonate derivatives.</p><p>Oligonucleotides modified with pyridylphosphonate internucleotide linkages have been prepared and preliminary studies on their hybridisation properties and resistance towards enzymatic degradation were performed.</p><p>Finally, nucleotidic units for the incorporation of pyridylphosphonate groups at the 5’-terminus of oligonucleotides were designed. Condensations of such units with a suitably protected nucleoside afforded after oxidation the expected dinucleoside (3’-5’)-phosphates with pyridylphosphonate monoester functions at the 5’-ends.</p>

<p>The goals for the project “Synthesis and Functionaliszation of 3-Nitropyridines” were first to further optimize the procedures for nitration of 3-nitropyridines, and then investigate some aspects of the mechanism. Further was the reactivity of 3- nitropyridines investigated, especially the reactivity toward nitrogen nucleophiles.</p><p>Pyridines can be nitrated by reacting the pyridine with dinitrogen pentoxide in an organic solvent and then pour the slurry formed into an aqueous solution of sodium bisulfite. After some hours of stirring, the 3-nitropyridine can be isolated.</p><p>After investigation of the effect of changes in sodium bisulfite concentration, reaction medium and temperature a modified procedure for the nitration was developed. In this procedure the pyridine compound was reacted with dinitrogen pentoxide in dichloromethane or nitro methane and the resulting slurry poured into a solution of bisulfite dissolved in methanol/water (3:1). After some hours of stirring at room temperature the 3-nitropyridine was isolated.</p><p>The mechanism of the nitration of pyridines with dinitrogen pentoxide was studied, and is shown in the next scheme. The author studied the migration of the nitro group from the nitrogen to the -carbon. It has been by others shown that pyridine and dinitrogen pentoxide forms N-nitro pyridinium nitrate. Which is attacked by the bisulfite nucleophile in either 2- or 4- position to give N-nitro-2- dihydropyridine-2-sulfonate and N-nitro-1,4-dihydropyridine-4-sulfonate. The nitro group in N-nitro-2-dihydropyridine-2-sulfonate migrates to the -carbon, to give via addition of one more bisulfite ion a tetrahydro intermediate. From this the 3-nitropyridine is formed by loss of two bisulfite ions. The mechanism for the nitro group migration was previously not known. The results presented in this thesis together with previous results conclude with that the migration takes place as a [1,5] sigmatropic shift.</p>

The goals for the project “Synthesis and Functionaliszation of 3-Nitropyridines” were first to further optimize the procedures for nitration of 3-nitropyridines, and then investigate some aspects of the mechanism. Further was the reactivity of 3- nitropyridines investigated, especially the reactivity toward nitrogen nucleophiles. Pyridines can be nitrated by reacting the pyridine with dinitrogen pentoxide in an organic solvent and then pour the slurry formed into an aqueous solution of sodium bisulfite. After some hours of stirring, the 3-nitropyridine can be isolated. After investigation of the effect of changes in sodium bisulfite concentration, reaction medium and temperature a modified procedure for the nitration was developed. In this procedure the pyridine compound was reacted with dinitrogen pentoxide in dichloromethane or nitro methane and the resulting slurry poured into a solution of bisulfite dissolved in methanol/water (3:1). After some hours of stirring at room temperature the 3-nitropyridine was isolated. The mechanism of the nitration of pyridines with dinitrogen pentoxide was studied, and is shown in the next scheme. The author studied the migration of the nitro group from the nitrogen to the -carbon. It has been by others shown that pyridine and dinitrogen pentoxide forms N-nitro pyridinium nitrate. Which is attacked by the bisulfite nucleophile in either 2- or 4- position to give N-nitro-2- dihydropyridine-2-sulfonate and N-nitro-1,4-dihydropyridine-4-sulfonate. The nitro group in N-nitro-2-dihydropyridine-2-sulfonate migrates to the -carbon, to give via addition of one more bisulfite ion a tetrahydro intermediate. From this the 3-nitropyridine is formed by loss of two bisulfite ions. The mechanism for the nitro group migration was previously not known. The results presented in this thesis together with previous results conclude with that the migration takes place as a [1,5] sigmatropic shift.

In this thesis, mechanistic and synthetic studies on transformations of H-phosphonates into DNA analogues containing P-S or P-C bonds are described. Configurational stability of dinucleoside H-phosphonates and the stereochemical course of their sulfurisation in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) were investigated. In light of these studies, the reported stereoselective sulfurisation of dinucleoside H-phosphonates and benzoylphosphonates in the presence of DBU was proved to be incorrect. Efficient protocols for the synthesis of new nucleotide analogues with non-ionic C-phosphonate internucleotide linkages were developed. The synthesis of dinucleoside 2-pyridylphosphonates was successfully performed by a DBU-promoted reaction of H-phosphonate diesters with N-methoxypyridinium salts. The thio analogues, 2-pyridyl- and 4-pyridyl phosphonothioate diesters, could be obtained by modifying the reactions developed for their oxo counterparts. Dinucleoside 3-pyridylphosphonates were prepared via a palladium(0)-catalysed cross coupling strategy that could be extended also to the synthesis of nucleotide analogues with metal-complexing properties, i.e. terpyridyl- and bipyridylphosphonate derivatives. Oligonucleotides modified with pyridylphosphonate internucleotide linkages have been prepared and preliminary studies on their hybridisation properties and resistance towards enzymatic degradation were performed. Finally, nucleotidic units for the incorporation of pyridylphosphonate groups at the 5’-terminus of oligonucleotides were designed. Condensations of such units with a suitably protected nucleoside afforded after oxidation the expected dinucleoside (3’-5’)-phosphates with pyridylphosphonate monoester functions at the 5’-ends.

In the present thesis, the effects of the carbonate radical anion on lignin and cellulose were investigated. The carbonate radical has a rather high reactivity towards aromatic lignin constituents. It reacts especially fast with phenolates. All these reactions occur by way of electron transfer. Small carbohydrates react with CO3 •- much slower than aromatics. These reactions are hydrogen transfer reactions. However, in very basic media, where the carbohydrates deprotonate to some extent, their anions react with CO3 •- by way of electron transfer and the rates approach those of non-phenolic aromatics. These findings suggest that in neutral or slightly alkaline media CO3 •- might serve as an excellent delignifying agent of pulp down to very low lignin contents. With small carbohydrates possessing one or two glucosidic bonds, CO3 •- abstracts hydrogen predominantly from C1 – H bonds, which results in rupture of the glucosidic linkage. Interestingly, however, the glucosidic bonds in cotton linters are rather resistent towards CO3 •-. This has probably morphological reasons. These results imply that, even at very low lignin contents, where CO3 •- is bound to react with cellulose, the reactions will not lead to substantial decrease in pulp viscosity. At present the cheapest and most practical way of producing CO3 •- radicals in the presence of pulp is to mix the latter with peroxynitrite and CO2. We have performed such experiments on pulp with very promising results. The Kappa number decreased substantially, brightness increased, while the viscosity remained high. This confirms the predicted excellent properties of the carbonate radical. However, before the peroxynitrite method can be implemented in the pulp industry, a number of technical problems has to be solved. Chief among them is a slow and steady dosage of peroxynitrite to minimise side reactions of the radicals with peroxynitrite and the nitrite impurity. The fate of the •NO2 radical, the coproduct of CO3 •-, has also to be assessed. •NO2 will probably have to be removed by vigorous degassing in order to block the possible nitration of cellulose. / QC 20101001

Compounds containing main-group clusters, with focus on bismuth polycations, have been synthesized and characterized using X-ray diffraction and spectroscopic methods. Six new compounds have been isolated from synthesis in GaX3-arene media; Bi8[GaCl4]2, Bi8 [GaBr4]2, Sb8[GaCl4]2, Sb8[GaBr4]2, Te4[Ga2Cl7]2 and Te4[Ga2Br7]2. Sb2+ 8 is the first homopolyatomic antimony cation to be isolated. The cation forms a square antiprism, in correlation with Wade’s rules, and displays a significant difference in length between the inter-square and intra-square Sb–Sb distances. The geometries of the Sb2+ 8 cations in Sb8[GaCl4]2 and Sb8[GaBr4]2 are in excellent agreement; the average intra-square and intersquare Sb–Sb distances are 2.87 Å and 2.97 Å, respectively. A very strong Raman band attributed to Sb2+8 is found at 180 cm-1. The Bi2+8 (square antiprismatic) and Te2+4 (squareplanar) polycations are known from earlier compounds. The Bi–Bi distances in Bi8[GaCl4]2 (3.07–3.12 Å) are in general agreement with previous structures, while the Bi–Bi distances of Bi8[GaBr4]2 (2.92–3.18 Å) display a wider distrubution than previously observed. The Te–Te distances of the cations of Te4[Ga2Cl7]2 and Te4[Ga2Br7]2 are 2.66 and 2.67 Å, respectively. Quantum chemical calculations on bismuth polycations show that all species predicted byWade’s rules are local minima on a potential energy surface. The cation–anion interactions have been considered for salts containing bismuth polycations and it has been confirmed that such interactions have a major influence on the polycation stability. The new compound Bi16I4 has been isolated from molten Bil3. The structure consists of polymerized Bi16I4 molecules forming infinite ribbons and is very similar to the structure of the known metal-rich bismuth iodides, Bi14I4 and Bi18I4. DFT calculations predict all three compounds to be metallic conductors, while Bi4I4 is a semiconductor. / QC 20101021

Syftet med detta arbete är att ge en bild av hur bedömning och betygsättning sker i kemiundervisningen i gymnasiet idag. Utsagor från intervjuade lärare tyder på att det ses som en viktig uppgift, används både i formativt och summativt syfte och tar tid. Ofta väger skriftliga prov, laborationsrapporter samt aktivitet under lektionstid tyngst för betyget, men hänsyn tas till många aspekter och delmoment. Projektarbeten och fördjupningar uppges av en av fem lärare som tungt vägande och bedöms utifrån muntliga redovisningar. Vid bedömningar används nationella målkriterier samt lokala eller personliga kriterier, som utgår från de nationella. De av Skolverket rekommenderade bedömningsmatriserna med både på förhand bestämda kriterier och kvalitetsnivåbeskrivningar används ej och inte heller nämns lokala arbetsplaner. Resultatet visar slutligen att det finns en frustration över betygskriteriernas otydlighet, som anses leda till att lärare gör sinsemellan olika bedömningar. / The focus in this report is assessment practice in chemistry education in upper secondary schools. Statements from interviewed teachers point to that assessment is thought of as an important task, is used in both formative and summative purposes and takes long time. Written exams, lab-reports and activity during lessons often are the most important aspects for the mark, but many factors and other activities are also considered. One of five teachers specified projects, like literature studies, to be of importance for the mark and assessed these based on oral presentations. When assessing, the teachers use national goal-referenced criteria and local or personal criteria, based on the national. The Swedish Board of Education recommends the use of rubrics, with beforehand formulated criteria and quality level descriptions. This is not mentioned as being used and neither are local educational plans. The result shows a frustration over the difficulty to interpret the mark criteria that is considered to result in differences in assessments among teachers.

Diss. (sammanfattning) Linköping : Linköpings universitet, 2005. / Härtill tre uppsatser.