Propagation and scattering of light in stratified media

The propagation and scattering of light in stratified media are considered. Based on the Maxwell equations, the present approaches to the solution of these problems are formulated in a unified way. The particular features of the wave propagation in stratified media are discussed. Scalar and vector fields are considered. Media with small-and large-scale regular inhomogeneities are examined. The construction of the Green’s function of the wave equation in a spatially homogeneous medium is discussed. Stratified isotropic and anisotropic media are analyzed. The scattering of light in a stratified medium is studied with emphasis on the Kirchhoff method, as this makes it possible to obtain calculation formulas in a form convenient for comparing the theory with the experiment. The propagation of waves in photonic crystals and the formation of forbidden zones in such objects are briefly considered.     

Light scattering in cholesteric liquid crystals with a large pitch

Optical properties of cholesteric liquid crystals with a pitch larger than the wavelength of light are considered. Normal waves of the medium and the Green function of the electromagnetic field are analyzed. A general algorithm based on the application of the Kirchhoff method is proposed for calculating the scattered light intensity in media with a one-dimensional periodic structure. The WKB vector method is used for calculating the spatial correlation function of thermal fluctuations of the director. It is found that the transformation of two fluctuation modes takes place is some regions. The angular and polarization dependences of the intensity of light scattered from fluctuations of the director are calculated. It is found, in particular, that the intensity of scattering is a nonmonotonic function of the size of the system.     

Synthesis and Analgesic Activity of New Heterocyclic Cyanothioacetamide Derivatives

Russian Journal of General Chemistry - The reaction of cyanothioacetamide with aromatic aldehydes and 1,3-dicarbonyl compounds followed by aminomethylation or S-alkylation gave a series of...     

Unusual regioselective reaction of 2,6-dichloro-4-methylnicotinonitrile with malononitrile dimer

Russian Chemical Bulletin - The reaction of 2,6-dichloro-4-methylnicotinonitrile with malononitrile dimer in the presence of triethylamine leads to regioselective nucleophilic substitution of the...     

Novel three-component peri-annelation reactions of carbocyclic and pyridine rings with perimidines—synthesis of 1,3-diazapyrenes and 1,3,7-triazapyrenes

A new effective synthetic method for 1,3-diazapyrenes and 1,3,7-triazapyrenes is developed based on the three-component reaction of perimidines or 1,8-diaminonaphthalene with 1,3,5-triazines and carbonyl compounds or benzonitrile in polyphosphoric acid (PPA).     

Formylation and acetylation of 2-ethoxynaphthalene with 1,3,5-triazines in polyphosphoric acid

Heating of 2-ethoxynaphthalene with 1,3,5-triazine or 2,4,6-trimethyl-1,3,5-triazine in polyphosphoric acid leads to the corresponding products of mono- or diacylation: 2-ethoxy-naphthalene-1-carbaldehyde, 1-acetyl-2-ethoxynaphthalene, 2-ethoxynaphthalene-1,8-dicarb-aldehyde, and 1,8-diacetyl-2-ethoxynaphthalene in ∼60–80% yield. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 207–208, January, 2008.     

Novel three-component reaction of perimidines with 1,3,5-triazines and carbonyl compounds in polyphosphoric acid. an efficient method for <Emphasis Type="Italic">peri</Emphasis>-annelation of a carbocyclic and pyridine ring

Methods have been developed for the synthesis of 1,3-diazapyrenes, 8(6)-aryl-6(8)-oxo-1,6,7,8-tetra-hydro-1,3-diazapyrenes, and 1,3,7-triazapyrenes based on a three-component reaction of perimidines with 1,3,5-triazines and carbonyl compounds, benzonitrile, or vinyl butyl ether in polyphosphoric acid.