Synthesis of alkyl 4-aryl-2-methyl-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylates

Reactions of alkyl acetoacetates, aromatic aldehydes, ammonium acetate, and 1,3-cyclohexanedione afford alkyl 4-aryl-2-methyl-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylates. The structure of compounds obtained was established with the help of IR, ¹H NMR, and mass spectra and by X-ray diffraction analysis.     

Nonlinear waves in para-and ferroelectrics described by the Landau-Khalatnikov equation

The propagation of an extremely short (one cycle long) pulse of an electromagnetic field in a medium with two equilibrium states is considered theoretically. The analysis is based on the set of Maxwell equations and the Landau-Khalatnikov equation, in which the approximations of the slowly varying envelopes are not used. The solutions of this set that describe the steady-state propagation of a solitary polarization wave and of an electromagnetic pulse are found. In the approximation of a unidirectional wave, a numerical simulation of the propagation and interaction of solitary waves is performed in terms of the model considered.     

Zeta Potential,Size, and Semiconductor Properties of Zinc Sulfide Nanoparticles in a Stable Aqueous Colloid Solution

A stable aqueous colloid solution of zinc sulfide (ZnS) nanoparticles was obtained by chemical condensation using ethylenediaminetetraacetic acid disodium salt. The mechanism of prolonged aggregative stability of solution at pH 7–8 with ~7-nm nanoparticles was determined as a result of the zeta potential measurements by dynamic light scattering. The blue and red shifts of the fundamental absorption edge of zinc sulfide semiconductor nanoparticles associated with the small size of nanoparticles and the defective state of their surface were found by optical spectrophotometry.     

Synthesis of polyfluoralkylated 1,3,2-dioxaphospholane and 1,3,2-dioxaphosphorinane oxides

Polyfluoroalkyl dichlorophosphates easily react with 1,2- or 1,3-alkanediols in a system pyridine–diethyl ether and afford 2-polyfluoroalkoxy-1,3,2-dioxaphospholane oxides or 2-polyfluoroalkoxy-1,3,2-dioxaphosphorinane oxides. In similar conditions the reaction of methyl dichlorophosphate with 1,2- and 1,3-alkanediols proceeds less effectively.     

A waveguide amplifier based on a counterdirectional coupler

The propagation of continuous-wave radiation in tunnel-coupled waveguides, one of which is characterized by a negative refraction and linear losses while the other is made of an ordinary dielectric and represents a linear amplifier, is analyzed theoretically. We found that, in the case of linear waveguides, the losses can be compensated at certain values of the pump-wave amplitude depending on values of the gain and loss coefficients in the corresponding waveguides, resulting in the amplification of radiation at the output of the waveguide with the negative refraction. The Kerr nonlinearity of the amplifying waveguide prevents the compensation of losses due to the violation of the phase-matching condition between the coupled waves in a counterdirectional coupler.     

Facile Exchange of Phosphoryl Oxygen by Sulfur and Selenium in Teriary Phosphine Oxides

Russian Journal of General Chemistry -