Structure, resolution and chiroptical analysis of stable lanthanide complexes of a pyridylphenylphosphinate triazacyclononane ligand

Lanthanide complexes of a pyridylphenylphosphinate ligand based on triazacyclononane form an isostructural series. The C(3)-symmetric Δ and Λ complexes of Eu and Tb are strongly emissive and can be resolved by chiral HPLC; the absolute configuration of each complex has been assigned using CD and CPL measurements.     

An electrostatic elliptical mirror for neutral polar molecules

Focusing optics for neutral molecules finds application in shaping and steering molecular beams. Here we present an electrostatic elliptical mirror for polar molecules consisting of an array of microstructured gold electrodes deposited on a glass substrate. Alternating positive and negative voltages applied to the electrodes create a repulsive potential for molecules in low-field-seeking states. The equipotential lines are parallel to the substrate surface, which is bent in an elliptical shape. The mirror is characterized by focusing a beam of metastable CO molecules and the results are compared to the outcome of trajectory simulations.     

Stereoselective synthesis of syn and anti 1,2-hydroxyalkyl moieties by Cu-catalyzed asymmetric allylic alkylation

A stereoselective synthesis of 1,2-hydroxyalkyl moieties is described herein. These valuable building blocks are obtained with complete regiocontrol and excellent stereocontrol both for the syn or the anti products, by choosing the appropriate enantiomer of the ligand in a copper-catalyzed asymmetric allylic alkylation of δ-alkoxy-substituted allyl bromides.     

Tunable plasmon coupling in distance-controlled gold nanoparticles

Plasmons are resonant excitations in metallic films and nanoparticles. For small enough static distances of metal nanoparticles, additional plasmon-coupled modes appear as a collective excitation between the nanoparticles. Here we show, by combining poly(N-isopropylacrylamide) micro- and nanospheres and Au nanoparticles, how to design a system that allows controllably and reversibly switching on and off, and tuning the plasmon-coupled mode.     

Oil powders and gels from particle-stabilized emulsions

We report on the use of silica particle-stabilized oil-in-water emulsions as a template for the preparation of oil powders and gels obtained in a single step by either slow or rapid evaporation of water using freeze-drying or spray-drying, respectively. Using olive oil and partially hydrophobic fumed silica nanoparticles, an oil powder containing nearly 90 wt % oil can be formed by spray-drying, which shows no sign of oil leakage over several months. Upon slow evaporation of water by freeze-drying, a transparent oil gel with oil content as high as 98 wt % can be formed, in which the silica particles form a space-filling network thickening the oil. Comparisons are made throughout with a typical surfactant-stabilized emulsion which does not produce oil powders or gels.     

Continuous‐Flow Reactor‐Based Enzymatic Synthesis of Phosphorylated Compounds on a Large Scale

Acid phosphatase, an enzyme that is able to catalyze the transfer of a phosphate group from cheap pyrophosphate to alcoholic substrates, was covalently immobilized on polymethacrylate beads with an epoxy linker (Immobeads‐150 or Sepabeads EC‐EP). After immobilization 70 % of the activity was retained and the immobilized enzyme was stable for many months. With the immobilized enzyme we were able to produce and prepare D ‐glucose‐6‐phosphate, N‐acetyl‐D ‐glucosamine‐6‐phosphate, allyl phosphate, dihydroxyacetone phosphate, glycerol‐1‐phosphate, and inosine‐5′‐monophosphate from the corresponding primary alcohol on gram scale using either a fed‐batch reactor or a continuous‐flow packed‐bed reactor.     

WEFTA interlaboratory comparison on total lipid determination in fishery products using the Smedes method

Lipid determination by the Smedes method was tested in an interlaboratory trial performed by nine laboratories from seven countries belonging to the West European Fish Technologists Association Analytical Methods Working Group. Five samples of fish and fishery products with different lipid contents, including two blind duplicates, were distributed among the participants. All laboratories applied a slightly modified Smedes method, which included extraction of lipids by cyclohexane and isopropanol, transfer of lipids to the cyclohexane phase by addition of water, phase separation by centrifugation, and gravimetric lipid determination. The results indicate that the RSD for reproducibility (RSD(R)) was between 4.11 and 6.31% for samples with moderate (7%) and high (14%) lipid content, depending on the sample. Larger SDs among the laboratories were obtained for a cod sample with low lipid content of 0.5%. The method is judged to be suitable as a routine method for lipid determination in fish and fishery products.