478 research outputs found
Dipole moments of para-substituted styrylphosphonates
1. The dipole moments of the dichlorides and diethyl esters of the styryl- and p-chlorostyrylphosphonic acids were determined. In the diethyl ester of p-chlorostyrylphosphonic acid the diethoxyphosphono group takes a substantial part in the common conjugation chain. 2. The diethoxyphosphono group and the phenyl ring in the diethyl esters of the p-halo- and p-nitro-α-cyanostyrylphosphonic acids are found in the trans-position. © 1972 Consultants Bureau, a division of Plenum Publishing Corporation
Reaction of α-Vinylallenylphosphonates with Diazoalkanes
Diazomethane reacts with 3-methyl-1-vinyl-1,2-butadienylphosphonates following the scheme of [3 + 2]-cycloaddition at the 1,2-double bond of the allenic fragment. The reaction with diphenyldiazomethane involves the vinyl fragment and yields substituted diphenylcyclopropane
An experimental and theoretical study of intramolecular cyclization of phosphorylated thioureas
New 1,3,2-thiazaphospholines were prepared, and their steric and electronic structures were examined. The steric and electronic structure of N-[(O-methyl)chloromethylthiophosphoryl]thiourea and the pathways of their intramolecular cyclization and rearrangement were studied by ab initio and semiempirical methods. The influence exerted by the conformational factors in thiourea and in the anion formed from it under the conditions of base catalysis on the direction of the reactions involving these species was revealed, and the structure of intermediate complexes and the final products was determined. ©2005 Pleiades Publishing, Inc
Reactions of phosphorylated allenes with dithiocarbamates
The addition of morpholino-, piperidino-, and N,N-diethyldithiocarbamate anions to 1,2-propadiene- and 1,2-butadienephosphonates proceeds on the electrophilic 1,2-double bond of the allene system with the formation of linear dithioesters. 1-Vinylallenylphosphonates add dithiocarbamate anions on the 1,3-conjugated system of multiple bonds, forming a mixture of stereoisomeric dithioesters with a diene structure. © 1990 Plenum Publishing Corporation
Multivariate statistic analysis of the world population ageing
© 2014, Mediterranean Center of Social and Educational Research. All right reserved. The research is devoted to the issue of the ageing of population, which is one of the global problems of the modern world. World countries have been grouped according to the amount of people over 65 years old. The conclusions about spatial differentiation of the ageing population have been drawn. The groups of states with a different level of population ageing were singled out. The amount of ageing population have been forecasted
Effects of substituents in reactions of sulfenyl chlorides with derivatives of phosphonallenic acids
In the reaction of sulfenyl chlorides with derivatives of allenylphosphonic acid, the structure of the products formed is determined by the effect of substituents at the P atom and the terminal C atom of the cumulene, and also by the nature of the organyl group attached to the S atom in sulfenyl chloride. © 1984 Plenum Publishing Corporation
Dipole moments of organophosphorus compounds. 15. Polarities and polarizabilities of some acetylenic compounds
1. Effective P-Csp bond dipole moments have been calculated for the oxides of diethyl and diphenylpropynylphosphines, and for the dichloroanhydride of propynylphosphonic acid. 2. The form with gauche orientation of the phosphoryl and ethoxy groups is preferred in the 0,0-diethyl ethynyl -and 0,0-diethyl propynylphosphonates. 3. The C-CH3 bonds of the ethyl and phosphoryl groups are in gauche orientation in diethylpropynylphosphine oxide. The structure of diphenylpropynylphosphine oxide is such that the phenyl radical planes are close to ethynyl group shielding. © 1978 Plenum Publishing Corporation
Dipole moments of organophosphorus compounds - Communication 1. Diethyl esters of substituted α-cyanostyrylphosphonic acids
1. The dipole moments of the diethyl esters of vinyl-1,3-butadiene- and α-cyanostyrylphosphonic acids were determined. 2. An interaction of the diethoxyphosphonic group with the π-electron system was detected, and the structure of the investigated compounds was determined. © 1971 Consultants Bureau
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