Synthesis of Novel α‐(Acyloxy)‐α‐(quinolin‐4‐yl)acetamides by a Three‐Component Reaction between an Isocyanide,Quinoline‐4‐carbaldehyde,and Arenecarboxylic Acids

Novel α‐(acyloxy)‐α‐(quinolin‐4‐yl)acetamides were synthesized by the Passerini three‐component reaction between an isocyanide, quinoline‐4‐carbaldehyde, and arenecarboxylic acids in H₂O. The reactions were carried out in one pot at room temperature with quantitative yields.     

Gas spectroscopy and temperature measurement by coherent Raman anti-stokes scattering

The feasibility of Raman spectroscopy and temperature measurements in gases by Coherent Anti-Stokes Scattering is discussed and demonstrated experimentally. Results are presented for H₂ gas at room temperature and also for H₂ liberated by pyrolysis in a Bunsen flame.     

Diterpenic skeleton transformations : alumina catalysed rearrangements of epoxides

The 8,14 β-epoxide of methyl sandaracopimarate undergoes new rearrangements on contact with active alumina, yielding labdane and another compound having the cycloisopimarane skeleton.     

Discovery of powerful uranyl ligands from efficient synthesis and screening

New tripodal gem-(bis-phosphonates) uranophiles were discovered by a screening method that allowed for the selection of ligands with strong uranyl-binding properties in a convenient microtiter-plate format. The method is based on competitive uranium binding by using Sulfochlorophenol S as chromogenic chelate. This dye compound was found to present high uranyl complexation properties and allowed to highlight ligands presenting association constants for UO(2+)(2) up to 10(18) at pH 7.4 and 10(20) at pH 9. A collection of 40 known ligands including polycarboxylate, hydroxamate, catecholate, hydroxypyridonate and hydroxyquinoline derivatives was tested. Also screened was a combinatorial library prepared from seven amine scaffolds and eight acrylates bearing diverse chelating moieties. Among these 96 tested candidates, a tripod derivative bearing gem-bis-phosphonates moieties was found to present the highest complexation properties over a wide range of pH and was further studied.     

Colloidal FeIII,MnIII, CoIII,and CuII Hydroxides Stabilized by Starch as Catalysts of Water Oxidation Reaction with One Electron Oxidant Ru(bpy)33+

Colloidal catalysts for oxidation of water to dioxygen, which are stable on storage and under the reaction conditions, are synthesized based on Co^III, Mn^III, Fe^III and Cu^II hydroxides. Stabilization of the colloids with dextrated starch allows the process of hydroxide ageing to be stopped at the stage of the formation of primary nuclei (ca. 2–3 nm from transmission electron microscopy data). Molecular mechanics and dynamic light scattering studies indicate a core-shell type structure of the catalysts, where the hydroxide core is stabilized by the molecular starch network (ca. 5–7 nm). The colloidal catalysts are highly efficient in oxidizing water with one electron oxidant Ru(bpy)₃³⁺ at pH 7 to 10. The influence of pH, catalyst concentration, and buffer nature on the oxygen yield is studied. The maximal yields are 72, 53, and 78 % over Fe-, Mn- and Co-containing catalysts, respectively, and turnover numbers are 7.8; 54 and 360, respectively. The Cu-containing catalyst is poorly effective to the water oxidation (the maximal yield is 28 % O₂). The synthesized catalysts are of interest for stopped-flow kinetic studies of the mechanism of the water oxidation and as precursors for anchoring nanosized hydroxides onto various supports in order to develop biomimetic systems for artificial photosynthesis.     

Estimates of the Dependence of the Fusion Neutron Yield on the Initial Plasma Density and Temperature in Fast Pinches

JETP Letters - The neutron generation by hot, dense, and fast Z- and Θ-pinch plasma with the parameters achievable at the present development stage of high-power pulsed technology has been...     

Formation of Chiral Structures in Photoinitiated Formose Reaction

The possibility to synthesize biologically important sugars and other chiral compounds without any initiators in the UV-initiated reaction of formaldehyde in aqueous solution has been shown for the first time. An optically active condensed phase due to an sp³-hybridized carbon atom has been detected. It has been shown that this phase is formed due to the spatial cleavage of antipodes in the racemate, similar to the cleavage of enantiomers following the sign of chirality in the known experiments of Pasteur. The results have been obtained under the conditions that correspond to modern ideas about the form and vector of prebiological evolution and, therefore, can be of fundamental importance for understanding the processes of biopoiesis.     

Application of a two-length-scale field theory to the solvation of neutral and charged molecules

We develop a continuous self-consistent theory of solute-water interactions that allows determination of the hydrophobic layer around a solute molecule of any geometry, with an explicit account of solvent structure described by its correlation function. We compute the mean solvent density profile n(r) surrounding the solute molecule as well as its solvation free energy deltaG. We compare the two-length-scale field theory to the numerical data of Monte Carlo simulations found in the literature for spherical molecules and discuss the possibility of self-consistent adjustment of the free parameters of the theory. In the framework of this approach, we compute the solvation free energies of alkane molecules and the free energy of interaction of two spheres of radius R separated by the distance D. We describe the general setting of the self-consistent account of electrostatic interactions in the framework of our model where the water is considered not as a continuous medium but as a gas of dipoles. We analyze the limiting cases where the proposed theory coincides with the electrostatics of a continuous medium.