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Université de Neuchâtel

Conception de nanoparticules d’or liquides-cristallines via la chimie click et la métathèse croisée d’oléfines

Nguyen, Thanh Tung ; Deschenaux, Robert (Dir.)

Thèse de doctorat : Université de Neuchâtel, 2016.

Notre travail de thèse consiste à employer deux méthodes de synthèse: la cycloaddition 1,3-dipolaire de Huisgen entre un alcyne et un azoture en présence d’un catalyseur de cuivre (I) (appelée également "chimie click") et la métathèse croisée d’oléfines pour greffer des dendrons liquides-cristallins sur la surface de nanoparticules d’or (AuNPs). Ce travail est divisé en...

Université de Fribourg

Crystal structures of trans-di­chlorido­tetra­kis­[1-(2,6-diiso­propyl­phen­yl)-1H-imidazole-ΚN³]iron(II), trans-di­bromido­tetra­kis­[1-(2,6-diiso­propyl­phen­yl)-1H-imidazole-ΚN³]iron(II) and trans-di­bromido­tetra­kis­[1-(2,6-diiso­propyl­phen­yl)-1H-imidazole-ΚN³]iron(II) diethyl ether disolvate

Mafua, Roger ; Jenny, Titus ; Labat, Gael ; Neels, Antonia ; Stoeckli-Evans, Helen

In: Acta Crystallographica Section E Structure Reports Online, 2014, vol. 70, no. 8, p. 72–76

The title compounds, [FeCl₂(C₁₅H₂₀N₂)₄], (I), [FeBr₂(C₁₅H₂₀N₂)₄], (II), and [FeBr₂(C₁₅H₂₀N₂)₄]·2C₄H₁₀O, (IIb), respectively, all have triclinic symmetry, with (I) and (II) being isotypic. The FeII atoms in each of the structures are located on an inversion center. They have octa­hedral FeX₂N₄ (X = Cl and Br,...

Université de Fribourg

Growth of ice nanoparticles via uptake of individual molecules: pickup cross sections

Fedor, Juraj ; Lengyel, Jozef ; Kočišek, J. ; Poterya, V. ; Pysanenko, A. ; Svrčková, P. ; Fárník, M.

In: Journal of Physics: Conference Series, 2014, vol. 488, no. 10, p. 102016

We present cross sections for pickup of several atmospherically relevant molecules on ice nanoparticles with the 0.5-3 nm diameter range. The experimental values are supported by molecular dynamics simulations and analytical calculations based on long-range cluster-molecule potentials. The cross sections are all considerably larger than the geometrical cross section of nanoparticle and vary...

Université de Fribourg

Ab-initio crystal structure analysis and refinement approaches of oligo p-benzamides based on electron diffraction data

Gorelik, Tatiana E. ; Streek, Jacco van de ; Kilbinger, Andreas F. M. ; Brunklaus, Gunther ; Kolb, Ute

In: Acta Crystallographica Section B, 2012, vol. 68, no. 2, p. 171-181

Ab-initio crystal structure analysis of organic materials from electron diffraction data is presented. The data were collected using the automated electron diffraction tomography (ADT) technique. The structure solution and refinement route is first validated on the basis of the known crystal structure of tri-p-benzamide. The same procedure is then applied to solve the previously unknown crystal...

Université de Fribourg

On the coordination behaviour of NO₃⁻ in coordination compounds with Ag⁺Part 1. Solubility effect on the formation of coordination polymer networks between AgNO₃ and L(L= ethanediyl bis(isonicotinate) as a function of solvent

Robin, Adeline Y. ; Sagué, Jorge L. ; Fromm, Katharina M.

In: CrystEngComm, 2006, vol. 8, p. 403-416

The influence of the solubility of AgNO₃ in three solvent systems is studied for the reaction between AgNO₃ and the ligand L(= ethanediyl bis(isonicotinate)). Three solid state structures are obtained, differing in the relative ratio Ag : L in the first case, and in polymorphism in the second. The Ag–O(NO₃⁻) distance correlates strongly with the solubility of AgNO₃ in...

Université de Neuchâtel

Crystallographic Analysis of a Full-length Streptavidin with Its C-terminal Polypeptide Bound in the Biotin Binding Site

Le Trong, Isolde ; Humbert, Nicolas ; Ward, Thomas R. ; Stenkamp, Ronald E.

In: Journal of Molecular Biology, 2006, vol. 356, p. 738-745

The structure of a full-length streptavidin has been determined at 1.7 Å resolution and shows that the 20 residue extension at the C terminus forms a well-ordered polypeptide loop on the surface of the tetramer. Residues 150–153 of the extension are bound to the ligand-binding site, possibly competing with exogenous ligands. The binding mode of these residues is compared with that of biotin...

Université de Genève

Charging behavior of polyamines in solution and on surfaces : a potentiometric titration study

Čakara, Duško ; Borkovec, Michal (Dir.)

Thèse de doctorat : Université de Genève, 2004 ; Sc. 3555.

Constant-ionic strength potentiometric titrations were performed in order to determine the protonation behavior of polyamines, dissolved in aqueous medium, or adsorbed onto weakly acidic particles suspended in water, as a function of pH (proton binding isotherms). For this task, a high-precision potentiometric titrator was assembled. Protonation of several different generations and different...

Université de Genève

Investigation théorique du mécanisme de physisorption : application d'une méthode de partition fondée sur la fonctionnelle de la densité

Vulliermet, Nathalie ; Weber, Jacques (Dir.) ; Adam, Tomasz (Codir.)

Thèse de doctorat : Université de Genève, 2000 ; Sc. 3188.

Une étude théorique portant sur la structure et les fréquences vibrationnelles de petites molécules adsorbées sur des surfaces ioniques a été effectuée. Dans le modèle utilisé la surface (soit MgO(100), ZnO(10[1 surligné]) ou NaCl(100)) est représentée par un agrégat entouré de charges ponctuelles. L'énergie d'absorption de la molécule (CO, H₂O ou D₂O), à une géométrie...