Search for dissertations about: "isomerization"

Showing result 1 - 5 of 81 swedish dissertations containing the word isomerization.

  1. 1. Thermal Isomerization of Azobenzene Side Chain Copolymers

    Author : Viktoria Skeppstedt; Chalmers University of Technology; []
    Keywords : free volume; thermal isomerization; positron annihilation lifetime spectroscopy; physical ageing; phthalate; methyl methacrylate polymer; azo polymers; plasticization;

    Abstract : Irradiation of azobenzene induces isomerization between its trans- and cis forms. By introduction of azobenzene chromophores in polymers, it is possible to optically control a variety of polymer properties. The isomerization of azobenzene can be used to influence conformational, optical or surface properties of the poly mer material. READ MORE

  2. 2. Catalytic Methods to Convert Allylic Substrates through Hydride and Proton Shifts : Transition Metal-Catalyzed and Organocatalyzed Approaches

    Author : Samuel Martinez-Erro; Belén Martín-Matute; Franziska Schoenebeck; Stockholms universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Allylic substrates; Iridium catalysis; Base catalysis; Method development; Isomerization; Hydride shift; Proton shift; Mechanistic studies; Organic Chemistry; organisk kemi;

    Abstract : The present thesis describes the development of new catalytic protocols to transform allylic substrates into a wide variety of versatile carbonyl and vinyl organic compounds. All procedures that are described in this work have in common the existence of one or more hydrogen shifts as key steps in the mechanism of the reactions. READ MORE

  3. 3. Quantum Chemical Studies of Radical Cation Rearrangement, Radical Carbonylation, and Homolytic Substitution Reactions

    Author : Daniel Norberg; Nessima Salhi-Benachenhou; Sten Lunell; Tim Clark; Uppsala universitet; []
    Keywords : Quantum chemistry; quantum chemistry; coupled-cluster; density functional theory; meta-GGA; reaction mechanism; potential energy surface; isomerization; fragmentation; dissociation; condensation; addition; SH2; hydrogen abstraction; iodine atom transfer; complex; weakly interacting system; hyperfine coupling constant; Kvantkemi;

    Abstract : Quantum chemical calculations have been performed to investigate radical cation rearrangement, radical carbonylation, and homolytic substitution reactions of organic molecules. The rearrangement of the bicyclopropylidiene radical cation to the tetramethyleneethane radical cation is predicted to proceed with stepwise disrotatory opening of the two rings. READ MORE

  4. 4. Studies of Hydrogenations and Isomerizations of Olefins and Alkylations of Amines Using Iridium Catalysts

    Author : Jia-Qi Li; Pher Andersson; Jianliang Xiao; Uppsala universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Iridium; Asymmetric; Hydrogenation; Isomerization; Alkylation; Organisk kemi; Organic Chemistry;

    Abstract : This thesis describes three types of reactions that were carried out using iridium catalysts.The first type is the iridium-catalyzed asymmetric hydrogenation of olefins. In paper I, the preparation of a new type of bicyclic thiazole-phosphine based iridium complex was described. READ MORE

  5. 5. Ruthenium-Catalyzed Asymmetric Transfer Hydrogenation

    Author : Tove Slagbrand; Stockholms universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; allylic alcohols; asymmetric catalysis; isomerization; reduction; ruthenium;

    Abstract : This thesis covers the development of two new methods for the asymmetric reduction of ketones and ketone intermediates. The protocols developed are based on the use of a ruthenium pseudo-dipeptide catalyst that previously has been shown to be efficient and selective in the asymmetric reduction of carbonyl compounds. READ MORE