Ecotoxicity interspecies study of ionic liquids based on phosphonium and ammonium cations.

This work studies the effects of different bromide-based ionic liquids, with phosphonium and ammonium cations, towards several environmental biomodels: Daphnia magna, Allivibrio fischeri, Raphidocelis subcapitata. Results indicate that toxicity clearly depends on the biomodel, Allivibrio fischeri being the least sensitive one while Daphnia magna is more severely affected in the presence of the studied ionic liquids. In most of the cases, phosphonium moieties are less toxic than ammonium ionic liquids.

Study of Iron Piperazine-Based Chelators as Potential Siderophore Mimetics.

Gram-negative bacteria's resistance such as and the group to conventional antibiotics leads to therapeutic failure. Use of siderophores as Trojan horses to internalize antibacterial agents or toxic metals within bacteria is a promising strategy to overcome resistance phenomenon. To combat the sp, we have synthesized and studied two piperazine-based siderophore mimetics carrying either catecholate moieties () or hydroxypyridinone groups () as iron chelators.

Glycine-betaine-derived ionic liquids: Synthesis, characterization and ecotoxicological evaluation.

Ionic Liquids (ILs) are generically regarded as environmentally "harmless" and thus, assumed as "non-toxic". However, due to the endless design possibilities, their ecotoxicological profile is still poorly known. An accurate knowledge on the toxicity of a substance is required, under the scope of environmental regulation worldwide, before their application and commercialization.

Liquid crystal-based tunable photodetector operating in the telecom C-band.

Liquid crystal (LC) microcells monolithically integrated on the surface of InGaAs based photodiodes (PDs) are demonstrated. These LC microcells acting as tunable Fabry-Perot filters exhibit a wavelength tunability of more than 100 nm around 1550 nm with less than 10V applied voltage. Using a tunable laser operating in the S and C bands, photocurrent measurements are performed.

Dispersions of Goethite Nanorods in Aprotic Polar Solvents.

Colloidal suspensions of anisotropic nanoparticles can spontaneously self-organize in liquid-crystalline phases beyond some concentration threshold. These phases often respond to electric and magnetic fields. At lower concentrations, usual isotropic liquids are observed but they can display very strong Kerr and Cotton-Mouton effects (i.

Synthesis, iron(III) complexation properties, molecular dynamics simulations and P. aeruginosa siderophore-like activity of two pyoverdine analogs.

P. aeruginosa ranks among the top five organisms causing nosocomial infections. Among the many novel strategies for developing new therapeutics against infection, targeting iron uptake mechanism seems promising as P.

Isotropic Elastic Stress Induced Large Temperature Range Liquid Crystal Blue Phase at Room Temperature.

A thermodynamically stable blue phase (BP) based on the conventional rod like nematogen is demonstrated for the first time at room temperature by only diluting a chiral-nematic mixture with the help of some nonmesogenic isotropic liquid. It is observed that addition of this isotropic liquid does not only stabilize the BPs at room temperature, but also significantly improves the temperature range (reversible during heating and cooling) of the BPs to the level of more than 28 °C. Apart from that, we have observed its microsecond electro-optic response time and, external electric field induced wavelength tuning, which are the two indispensable requirements for next generation optical devices, photonic displays, lasers, and many more.

Evidence of chitosan-mediated reduction of Au(III) to Au(0) nanoparticles under electron beam by using OH˙ and e⁻(aq) scavengers.

Selective scavengers of e(-)(aq) and OH˙ radicals were used to investigate the radiolytic synthesis of gold nanoparticles from Au(III) solutions in the presence of chitosan. This reaction does not exclusively follow the direct reduction by solvated electrons. Irradiation generates short-lived and long-lived reductive species derived from chitosan that efficiently convert Au(III) into Au(0) which aggregates to form clusters.

Impact of the concentration in polymer on the dynamic behavior of Polymer Stabilized Ferroelectric Liquid Crystal using Snap-shot Mueller Matrix Polarimetry.

Experimental results are presented related to the dynamic behaviour of Polymer Stabilized Ferro-electric Liquid Crystal (PSFLC) samples under external applied electric field, using Snap-shot Mueller Matrix Polarimetry (SMMP) and Mueller Matrix (MM) formalism. Different polarimetric coefficients are simultaneously extracted from each channeled spectrum measured with this full-optical SMMP technique. The impact of the concentration of polymer present into the liquid crystal cell on this dynamic behaviour is studied, permitting a direct and quick characterisation of the material.

Synthesis, Physicochemical Studies, Molecular Dynamics Simulations, and Metal-Ion-Dependent Antiproliferative and Antiangiogenic Properties of Cone ICL670-Substituted Calix[4]arenes.

Iron chelators, through their capacity to modulate the iron concentration in cells, are promising molecules for cancer chemotherapy. Chelators with high lipophilicity easily enter into cells and deplete the iron intracellular pool. Consequently, iron-dependent enzymes, such as ribonucleotide reductase, which is over-expressed in cancer cells, become nonfunctional.

Time-resolved switching analysis of a ferroelectric liquid crystal by snapshot Mueller matrix polarimetry.

An experimental snapshot Mueller matrix polarimeter based on wavelength polarization coding is used to get a time-resolved description of electric-field-induced fast transition within a ferroelectric liquid-crystal cell. The parameters extracted from experimental Mueller matrices are linked to the molecule director distribution to further determine the average trajectory and the collective behavior of these molecules while they switch over to another state.

Synthesis, physico-chemical properties and complexing abilities of new amphiphilic ligands from D-galacturonic acid.

This paper describes a convenient and efficient synthesis of new complexing surfactants from d-galacturonic acid and n-octanol as renewable raw materials in a two-step sequence. In the first step, simultaneous O-glycosidation-esterification under Fischer conditions was achieved. The anomeric ratio of the products was studied based on the main experimental parameters and the activation mode (thermal or microwave).

Synthesis, characterization and dioxygen reactivity of copper(I) complexes with glycoligands.

A new family of copper(I) complexes with "glycoligands" containing a central saccharide scaffold, with 2-picolyl ether groups or 2-picolylamine or N-imidazolylamine groups, has been prepared and characterized. For this purpose, the following tetradentate ligands have been synthesized: methyl 2,3-di-O-(2-picolyl)-alpha-D-lyxofuranoside (L1), 1,5-anhydro-2-deoxy-3,4-di-O-(2-picolyl)-d-galactitol (L2), 5-(amino-N-(2-salicyl))-5-deoxy-1,2-O-isopropylidene-3-O-(2-picolyl)-alpha-D-xylofuranose (L3), and 5-(amino-N-(2-salicyl))-5-deoxy-1,2-O-isopropylidene-3-O-(methylimidazol-2-yl)-alpha-D-xylofuranose (L4). The ligands and the complexes were characterized by elemental analysis, IR, 1H and 13C NMR spectroscopies, ESI mass spectrometry, and cyclic voltammetry.

Thermodynamic and spectroscopic studies of Cu(II) and Ni(II) complexes with a new proline-threonine dipeptide ligand.

The interactions between a new proline-threonine dipeptide ligand with two metallic cations were investigated in aqueous solution. The metallic cations studied were the copper(II) and the nickel(II), which are involved in many biological processes. The combination of potentiometry, UV-visible spectrophotometry, EPR, and mass spectrometry was used to determine the formation constants of the complexes and their structure in solution.

Thermodynamic and spectroscopic studies of copper (II) complexes with three bis(amide) ligands derived from L-tartaric acid.

The interactions of three bis(amide) ligands derived from tartaric acid with copper (II) were investigated in aqueous solution by a combination of potentiometry, UV-vis spectrophotometry, electron paramagnetic resonance (EPR), and mass spectrometry. The formation constants of the complexes were measured and their relative structures were reported. The sites of complexation of these ligands are investigated based mostly on their electronic and EPR spectra and on the comparison with the behaviour of some analog compounds.

Use of analytical microscopy to analyze the speciation of copper and chromium ions onto a low-cost biomaterial.

In this paper, we present our study of the speciation of copper and hexavalent chromium sorbed onto a lignocellulosic substrate, using analytical microscopy. The lignocellulosic substrate constitutes a low-cost biomaterial that can be used in wastewater treatment. Transmission electron microscopy (TEM) coupled with energy-dispersive X-ray spectroscopy (EDXS) was used to determine the speciation of the two metal ions on the constitutive moieties of the lignocellulosic substrate.

EXAFS and XANES studies of retention of copper and lead by a lignocellulosic biomaterial.

Lignocellulosic substrate (LS), which is a low cost biomaterial, has a strong complexing ability and can be used in the treatment of wastewaters as biosorbentto remove heavy metals. The speciation of copper and lead to this biomaterial has been studied by X-ray absorption spectroscopy. The copper(II) has a 6-coordinate structure with four oxygen atoms in the equatorial plane at 1.