Analyse par spectrométrie d'absorption infrarouge jusqu'à - 180 °C,de la structure cristalline des mélanges chloroforme-acétonitrile et chloroforme-propionitrile

A study, by infrared spectroscopy between 5000 and 200 cm^?1, in the liquid and solid states down to ? 180 °C, confirms the results obtained by thermal analysis: there is a complex in the case of ethyl cyanide-chloroform mixtures, whereas in the case of methyl cyanide-chloroform mixtures a eutectic is obtained. Furthermore we show, by the analysis of vibrations of the molecular lattice obtained, that, in this eutectic, the chloroform influences the crystalline structure of methyl cyanide.     

Dispositif de prelevement microanalytique de produits alterables

A small glass device is described for microanalytical or submicroanalytical sampling of unstable solid or liquid substances, in an argon atmosphere.

Zusammenfassung

Ein kleines Glasgerät wird beschrieben, das die Probenahme für die Mikrooder Submikroanalyse instabiler fester oder flüssiger Substanzen in Argonatmosphäre erlaubt.     

Etude de l'action de l'oxyde d'azote (III) sur l'indène et ses homologues

Addition of nitrogen trioxide to indene and alkylindenes N₂O₃ adds to indene and homologous yelding pseudonitrosites which are converted to aminoindanes. Treatment of the pseudonitrosites with alcoholic potassium hydroxide gives the correspondent nitroindenes.     

Phosphorus-containing dendrimers bearing galactosylceramide analogs: self-assembly properties

We report the synthesis and the supramolecular auto-assembly of catanionic phosphorus-containing dendrimers mimicking multisite analogs of galactosylceramide.     

Theoretical and experimental characterization of amino‐PEG‐phosphonate‐terminated Polyphosphorhydrazone dendrimers: Influence of size and PEG capping on cytotoxicity profiles

The synthesis of new series of PPH (poly(phosphorhydrazone)) dendrimers with amino‐PEG phosphonates or the corresponding amino‐PEG phosphonic acids as terminal groups is presented, from generations 1–3. The size of PEG‐terminated dendrimers is experimentally measured by diffusional NMR, and by means of dynamic light scattering. Classical molecular dynamics and well‐tempered metadynamics simulations are used to assess or confirm the formation of aggregates in some cases. The influence of PEG capping on the cytotoxicity profiles of the dendrimers is evaluated on human peripheral blood mononuclear cells by means of LIVE/DEAD assays, and confirms the importance of PEG capping to ensure low cytotoxicity. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 761–774     

Dextran-coated silica nanoparticles for calcium-sensing

This article describes the synthesis and characterisation of fluorescent composite nanoparticles consisting of a silica core and a dextran shell. The silica core contains a rhodamine-based reference dye, which allows ratiometric measurements and the dextran shell is labelled with the Ca(2+)-sensitive dye Fluo-4. The nanoparticles have an average hydrodynamic diameter of 95 nm, good colloidal stability and show a 2.9-fold increase in fluorescence intensity upon binding to Ca(2+) ions. The apparent dissociation constant of K'(d) ≈ 520 nM is well suited for measurements in the physiological range.     

Janus carbosilane/phosphorhydrazone dendrimers synthesized by the ‘click’ Staudinger reaction

The first association of carbosilane dendrons (having a phosphine at the focal point) with phosphorhydrazone dendrons (having a thiophosphoryl azide at the focal point) has been successfully carried out by ‘Staudinger click’ reaction. The corresponding Janus dendrimers possess the characteristics of both components; they are oily as the carbosilane dendrons, and they can be easily functionalized as the phosphorhydrazone dendrons.     

Rational design of lanthanide binding peptides

Lanthanide-binding peptides are very attractive for the design of bioprobes. Indeed, they combine the amazing properties of lanthanide ions, such as their time-resolved luminescence (Eu, Tb) or electronic relaxation (Gd) to the characteristics of the peptide scaffold, such as large solubility in water and ability to recognize biological substrates. Peptides derived from natural amino acids are reviewed in a first section. Some of their lanthanide complexes have already demonstrated their efficiency in determining protein structures and functions. Then, we will show how insertion of chelating unnatural amino acids modulates peptide-lanthanide complexes properties, such as luminescence and stability.