Sökning: "chiral"

Visar resultat 1 - 5 av 372 avhandlingar innehållade ordet chiral.

  1. 1. Optical Investigations of Chiral Liquid Crystals

    Författare :Anders Dahlgren; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; antiferroelectric; de Vries theory; ferroelectric; optical activity; chiral; dielectric tensor; unwinding; liquid crystal; helicoidal; selective reflection;

    Sammanfattning : Optical investigations of course involve experimental work, but a theoretical basis is also needed. The first chapter can hopefully can give the non-expert an insight into the science of liquid crystals. Liquid crystals are optically birefringent, and a review of the phenomenon of birefringence follows in chapter 2. LÄS MER

  3. 2. Chiral Pyridine-Containing Ligands for Asymmetric Catalysis. Synthesis and Applications

    Författare :Fredrik Rahm; KTH; []
    Nyckelord :asymmetric catalysis; chiral ligand; chiral pool; oxazoline; crown ether; ditopic receptor; bipyridine; pyridyl alcohol; modular approach; P; N-ligand; diethylzinc; allylic alkylation;

    Sammanfattning : This thesis deals with the design and syntheses of chiral,enantiopure pyridinecontaining ligands and their applicationsin asymmetric catalyis.Chiral pyridyl pyrrolidine ligands and pyridyl oxazolineligands were synthesized and employed in thepalladium-catalysed allylic alkylation of 1,3-diphenyl-2-propenyl acetate with dimethyl malonate. LÄS MER

  4. 3. New Techniques for Chiral Separations

    Författare :Jeanette Olsson; Lars Blomberg; Steen Honoré Hansen; Karlstads universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; analytical chemistry; chiral separation; GC; CE; CEC; Analytical chemistry; Analytisk kemi; Kemi; Chemistry;

    Sammanfattning : Gas chromatography (GC) has been utilized for the study of enantiomer resolution of the atropisomers of PCBs, o,p´-DDD and o,p´-DDT. Different substituents and concentrations of cyclodextrin, capillary dimensions and type of stationary phase films have been investigated to achieve the resolution of as many of the atropisomers on one column as possible. LÄS MER

  5. 4. Development of New Chiral Bicyclic Ligands : Applications in Catalytic Asymmetric Transfer Hydrogenation, Epoxidations, and Epoxide Rearrangements

    Författare :Arnaud Gayet; Andersson Pher G.; Hilmersson Göran; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Organic chemistry; asymmetric catalysis; transfer hydrogenation; epoxide rearrangement; Organocatalysed epoxidation; chiral ligand; allylic alcohol; kinetic resolution; lithium amide; Organisk kemi; Organic chemistry; Organisk kemi;

    Sammanfattning : This thesis describes the synthesis and application of new chiral bicyclic ligands and their application in asymmetric catalysis. The studies involved: [i] The development of novel chiral bicyclic amino sulfur ligands and their use in transfer hydrogenation. LÄS MER

  7. 5. Interactions of chiral ions and molecules in gas phase : Towards an understanding of chiral recognition mechanism

    Författare :Oleksii Rebrov; Mats Larsson; Richard Thomas; Vitali Zhaunerchyk; Anne Zehnacker-Rentien; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; fysik; Physics;

    Sammanfattning : This thesis comprises the research related to interactions of enantiopure amino acids with chiral and achiral molecules in gas phase. The investigation of the mechanism responsible for chiral discrimination is of the special interest in this work. LÄS MER