Sökning: "attractive steric effect"

Hittade 3 avhandlingar innehållade orden attractive steric effect.

  1. 1. A study of the stereochemistry and electronic transitions of cyclic and acyclic thioamides by crystallography, spectroscopy and computational methods

    Författare :Knut Rang; Centrum för analys och syntes; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; UV and CD spectroscopy; rotational barriers; DNMR; X-ray; N -bis[ S -1-phenylethyl]-thiourea; N; attractive steric effect; chiral; phenyl or H- rhodanines; 3- alkyl or aralkyl -5- methyl; Conformations; electronic transitions; molecular mechanics; enantiom; Organic chemistry; Organisk kemi;

    Sammanfattning : Analysis of conformations and electron transitions of 3-(alkyl or aralkyl)-5-(methyl or phenyl)rhodanines with analogues and N,N'-bis[(S)-1-phenylethyl]-thiourea have been performed by X-ray crystallography, 1H NMR, molecular mechanics, ultraviolet spectroscopy and for the chiral rhodanines, enantiomer chromatography and circular dichroism spectroscopy. The magnitude of rotational barriers has been determined. LÄS MER

  3. 2. Chiral Liquid Crystalline Side-Chain Polymers. Design, Synthesis and Properties

    Författare :Magnus Svensson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; lateral substituent; electro-optic; ferroelectric; molar mass; polymer; side-group; thin film; polysiloxane;

    Sammanfattning : The potential use of chiral liquid crystalline materials, low molar mass as well as polymers, in technical applications has been recognized for some decades now. A number of interesting phenomena based on the spontaneous ordering of the liquid crystal forming molecules are strong reasons for the research effort in this area. LÄS MER

  4. 3. Surface reactivity, stability, and mobility of metal nanoparticles in aqueous solutions : Influence of natural organic matter and implications on particle dispersion preparation

    Författare :Sulena Pradhan; Inger Odnevall Wallinder; Jonas Hedberg; Eva Blomberg; Emma Strömberg; Kerstin Forsberg; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nanoparticles; freshwater; di-hydroxybenzoic acid; humic acid; copper; aluminium; manganese; dissolution; agglomeration; stability; complexation; Kemi; Chemistry;

    Sammanfattning : The growing development of nanotechnology has resulted in an increased use of nanoparticles (NPs) in various applications ranging from medicine, military, to daily consumer products. There is a concern that NPs can be dispersed into the environment in various ways, for example to air and water during manufacture, use, incineration or recycling of products and thus pose a risk to health and the environment. LÄS MER