A new approach to the synthesis of ethyl (4E)-alkenoates

A new approach to the preparation of ethyl (4E)-alkenoates was developed on the basis of Fe-catalyzed cross-coupling of ethyl (4E)-5-chloropent-4-enoate with the Grignard reagents. The starting ethyl (4E)-5-chloropent-4-enoate was obtained by alkylation of malonic ester of (E)-1,3-dichloropropene followed by decarbethoxylation.     

Liquid Ion-Selective Electrodes for Determining Nonionic Surfactants

It was shown that nonionic surfactants (NS) can be determined by potentiometry using liquid NS-selective electrodes. The effect of medium acidity and foreign substances on the operation of liquid NS-selective electrodes was studied. Some properties of NS-selective electrodes were determined.     

Fixation of micelle structure by monomer polymerization: Hydrodynamic properties of polymerized micelles

Polymerized and nonpolymerized micelles of N-acryloyl-11-aminoundecanoic acid and its sodium salt in water and dimethylformamide are studied by viscometry, isothermal diffusion, and dynamic light scattering. It is revealed that the hydrodynamic sizes of polymerized micelles (PMs) obtained via polymerization of the surfactants in aqueous solutions at low concentrations of the latter are significantly larger than those of the starting surfactant micelles. In dimethylformamide, as the surfactant concentration at which the synthesis is carried out is increased, the hydrodynamic size of PMs, which is calculated in terms of the cylindrical particle model, rises from 25 to 220 nm. The formation of additional internal crosslinks reduces the equilibrium rigidity of the PM chains by a factor of 1.5–2.     

Reactions of Lithium Acylates α-Carbanions with 1,2-Diiodoethane

Russian Journal of General Chemistry - The interaction of lithium acylates α-carbanions (obtained via metallation of acetic, butyric, and isobutyric acids with lithium diisopropylamide) with...     

Alternative synthesis of alverine

An efficient synthesis of alverine via iron-catalyzed double cross-coupling of (2E)-3-chloro-N-[(2E)-3-chloroprop-2-en-1-yl]-N-ethylprop-2-en-1-amine with phenylmagnesium bromide is described.     

Dynamic elasticity of films formed by poly(<Emphasis Type="Italic">N</Emphasis>-isopropylacrylamide) microparticles on a water surface

Surface dilatational dynamic elasticity ε of films formed by cross-linked poly(N-isopropylacrylamide) microparticles on a water/air interface has been determined as a function of polymer surface concentration Γ. The experimental dependences exhibit two maxima of ε at surface pressures π of nearly 6 and 35 mN/m. In the region of the second maximum, the pattern of the dependence is governed by a method used to vary Γ. At π > 25 mN/m, film compression leads to the formation of a metastable monolayer, while the gradual addition of a microparticle dispersion results in the establishment of equilibrium between the monolayer and surface aggregates. In the region of π values corresponding to the second maximum of ε, slow relaxation processes with a characteristic time substantially longer than 10 s occur in the system. At π > 35 mN/m, the film collapses due to the displacement of microgel particles from the water surface.     

Surface Tension and Dynamic Contact Angle of Water in Thin Quartz Capillaries

The surface tension of water has been measured in quartz capillaries with radii from 200 down to 40 nm. It appears that the surface tension does not differ from the known (bulk) values in the temperature range from 8 to 70 degrees C, within 1% experimental error. The dynamic contact angle, theta(d), vanishes when the capillary surface is covered with a wetting film left behind the receding meniscus. In the case of a dry surface, theta(d) depends on the velocity of the meniscus motion. The results obtained do not agree with presently available theoretical predictions from hydrodynamic theories of dynamic contact angles. Rather the kinetics of water vapor adsorption ahead of the moving meniscus seems to be the major controlling agent of the dynamic contact angle. Copyright 2000 Academic Press.     

Pheromones of insects and their analogs LIV. Synthesis of dodec-9E-en-1-ol and its acetate —components of the sex pheromone ofSparganothis pilleriana

Using the Claisen rearrangement in the construction of a double bond with the E configuration, we have synthesized dodec-9E-en-l-ol and its acetate, which are components of the sex pheromone ofSparganothis pilleriana.Scientific Research Institute of Fine Organic Synthesis of the Academy of Sciences, Republic of Belarus. Ufa State Petroleum Technical University. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 936–939, November–December, 1996. Original article submitted May 11, 1996.     

Features of microarc oxidation coatings formation technology in slurry electrolytes

A group of electrolytes composed of different powders entered into electrolyte presents a separate direction in microarc oxidation (MAO) technology. This group of electrolytes is most complex and however it has not been sufficiently studied yet. This paper shows that addition of powders of different nature into electrolyte influences both on properties of obtained coatings and on speed of their formation. The MAO-coatings formed in similar electrolytes-suspensions or slurry electrolytes (SE) contain in their composition an essential share of powder material entered into electrolyte as corpuscles of disperse phase (DP). Different nonmetallic combinations are used: oxides, carbides, borides, nitrides of metals and others. The particular conditions of microarc discharge regime (high temperature and pressure in a zone of breakdown) cause a thermolysis of electrolyte together with weighed corpuscles of solid matter, the realization of plasma chemical reactions on oxidizing surface and provide the synthesis of chemical combinations in an oxide matrix. A new composition of slurry electrolyte which allows improving the quality of obtained coatings on the basis of held investigations was developed.     

Hydrogen-like atom with nonnegative quantum distribution function

Among numerous approaches to probabilistic interpretation of conventional quantum mechanics (CQM), the closest to N. Bohr’s idea of the correspondence principle is the Blokhintzev-Terletsky approach of the quantum distribution function (QDF) on the coordinate-momentum (q, p) phase space. The detailed investigation of this approach has led to the correspondence rule of V.V. Kuryshkin parametrically dependent on a set of auxiliary functions. According to investigations of numerous authors, the existence and the explicit form of QDF depends on the correspondence rule between classical functions A(q, p) and quantum operator A. At the same time, the QDF corresponding to all known quantization rules turns out to be alternating in sign or overly complex valued. Finally nonexistence of nonnegative QDF in CQM was proved. On the other hand, from this follows the possibility to construct quantum mechanics where a nonnegative QDF exists. We consider a certain set of auxiliary functions to construct explicit expressions for operators O(H) for the hydrogen atom. Naturally, these operators differ from the related operator Ĥ in CQM, so that spherical coordinates are no longer separable for a hydrogen-like atom in quantum mechanics with nonnegative QDF. The text was submitted by the authors in English.