Effect of the group velocity mismatch and dispersion of nonlinear susceptibility on the modulation instability of electromagnetic waves in a medium with quadratic nonlinearity

Modulation instability of continuous plane waves of the pump beams and the second harmonic that are described by the set of equations for the process of second-harmonic generation with allowance made for the dispersion of nonlinear susceptibility is considered. The case of type I phase matching is analyzed. In the regions of anomalous and normal group velocity dispersion, the instability increments are determined as functions of the frequency and the wave numbers of perturbations. It was found that the difference in the group velocities of the interacting waves exerts the most substantial effect on the evolution of the modulation instability.     

Reactions of Elemental Phosphorus and Phosphine with Electrophiles in Superbasic Systems: XV. Phosphorylation of Allyl Halides with Elemental Phosphorus

Elemental phosphorus (red or white) reacts with allyl chloride and allyl bromide in a two-phase system aqueous KOH-organic solvent to form tertiary symmetrical and mixed phosphine oxides among which tris(prop-2-enyl)-, bis(prop-2-enyl)[(E)-prop-1-enyl]-, bis(prop-2-enyl)[(Z)-prop-1-enyl]-, (prop-2-enyl)[(E)-prop-1-enyl][(Z)-prop-1-enyl]-, bis[(E)-prop-1-enyl](prop-2-enyl)-, bis[(Z)-prop-1-enyl](prop-2-enyl)-, tris-[(E)-prop-1-enyl]-, and bis[(E)-prop-1-enyl][(Z)-prop-1-enyl]phosphine oxides were identified. The conditions (room temperature, 60% aqueous KOH-dioxane) allowing preparation from white phosphorus and allyl bromide of tris(prop-2-enyl)- and bis(prop-2-enyl)[(E)-prop-1-enyl]phosphine oxides as major products in the total yield of up to 96% were found.     

Influence of isomerism of difluorobenzophenone on the synthesis and properties of poly(arylene ether ketones)

The influence of isomerism of difluorobenzophenone on the efficiency of polycondensation and the properties of homo- and copoly(arylene ether ketones) was studied. The latter were prepared by the reaction of 2,4"- and 4,4"-difluorobenzophenone with potassium diphenolates of bisphenol À and phenolphthalein in N,N-dimethylacetamide. A high content of an admixture of the 2,4"-isomer in 4,4"-difluorobenzophenone decreases the molecular weight of related poly(arylene ether ketones) and has no substantial effect on their glass transition temperature.     

4,5-dihydroisoxazoles from arylcyclopropanes: II. Reaction of arylcyclopropanes with nitrosyl chloride activated by sulfur(VI) oxide

Arylcyclopropanes react with nitrosyl chloride activated by sulfur(VI) oxide to give the corresponding 5-aryl-4,5-dihydro-1,2-oxazoles in quantitative yields. The complex NOC1·2SO₃ is a highly efficient nitrosating agent which makes it possible to involve in the process arylcyclopropanes having both donor and acceptor substituents in the aromatic ring.     

Synthesis of 1-[2-(1H-Indol-3-yl)ethyl]-4-acetyl-3-hydroxy-5-phenyl-1H-pyrrol-2(5H)-ones

Russian Journal of General Chemistry - 1-[2-(1H-indol-3-yl)ethyl]-4-acetyl-3-hydroxy-5-phenyl-1H-pyrrole-2(5H)-ones were synthesized by the short heating of a mixture of tryptamine, aromatic...     

Photoelectron spectroscopy of phenyldihalophosphites

In order to explain the reactivity of aryldihalophosphites towards halophosphomum salts, photoelectron spectra of PhOPX₂ (X=F, Cl) were studied. Electron densities of boundary molecular orbitals (MO) for these compounds were calculated using the MNDO method and analyzed. Replacement of F by Cl was shown to substantially affect the orbital. When X= Cl, this MO embraces the whole of the OPX₂ moiety whereas for X=F it is localized on the P-O bond.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 323–324, February, 1993.     

Cu-Catalyzed Oxidative Phosphorylation of Alkanols with White Phosphorus and H 2 O 2

Oxidative phosphorylation of alkanols with white phosphorus in the presence of catalytic amounts of CuCl 2 has been effected. The reaction proceeds in the aqueous H 2 O 2 --HCl system exothermically to form dialkylphosphites and trialkylphosphates in a total yield of up to 35%. Conditions for selective synthesis of dialkylphosphites in moderate yield have been found.