Conformation of cyanomethylphosphine oxides

1. The dipole moments of the diethyl- and diphenylcyanomethylphosphine oxides were determined, and from them was found the ratio of the conformers. 2. The relative stability of the conformers is determined by electrostatic interactions. © 1971 Consultants Bureau

Dipole moments and conformations of 2-(4-pyridyl)ethyl alkyl(aryl) sulfides

Study of the 2-(4-pyridyl)ethyl akyl sulfides has shown that these compounds exist as equilibrated mixtures of structures with trans- and gauche-oriented C-Py and C-S fragments, the content of the first making up 0.6-0.7 fraction of the whole. © 1977 Plenum Publishing Corporation

Dipole moments and structure of some cyclic phosphonic esters

1. We were the first to determine the group dipole moment of the 4,4,5,5-tetramethyl-2-oxo-1,3,2-dioxaphospholane ring, which is directed toward the exocyclic bond of phosphorus at an angle of 81°. 2. The 5,5-dimethyl-2-phenyl-2-oxo-and 2-p-chlorophenyl-2-oxo-1,3,2-dioxaphosphorinanes exist in solutions as a conformational equilibrium of the forms with an equatorial and axial P=O group, with predominance of the latter. © 1979 Plenum Publishing Corporation

Quantum-chemical calculation of 1-bis(dimethlamino)-4-bis(trimethylsilyl)- 2,3-diphospha-1,3-butadiene

According to the results of ab initio quantum-chemical calculation 1-bis(dimethylamino)-4-bis-(trimethylsilyl-2,3-diphosphabuta-1,3-diene exists as an E-isomer where electronic delocalization occurs involving donor dimethylamino and acceptor trimethylsilyl groups and also the multiple P=C bonds

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

Dipole moments and conformations of 2-(4-pyridyl)ethyl alkyl(aryl) sulfides

Study of the 2-(4-pyridyl)ethyl akyl sulfides has shown that these compounds exist as equilibrated mixtures of structures with trans- and gauche-oriented C-Py and C-S fragments, the content of the first making up 0.6-0.7 fraction of the whole. © 1977 Plenum Publishing Corporation

The dipole moments and structure of organophosphorus compounds: Vector-additive scheme

The dipole moments of bonds formed by phosphorus in different coordination states were generalized, tabulated, and analyzed. The general and "fractional" vector-additive schemes for calculating dipole moments are discussed. The high electronic lability of the majority of bonds formed by phosphorus was shown to require care in the use of their polarities for studying the spatial structure of organophosphorus derivatives and electronic interactions in them. In all instances, the environment of the phosphorus atom in model compounds should be closest to that in the molecule under study. Using the method of dipole moments in combination with the complementary electro- and magnetooptical and spectral methods increases the reliability of the results. Copyright © 2005 by Pleiades Publishing, Inc

Theoretical conformational analysis of organophosphorus compounds

Published data on the theoretical conformational analysis of acyclic tri- and tetracoordinate phosphorus compounds by quantum-chemical methods are generalised and systematised. Theoretical results are compared with experimental data for a wide range of such compounds. The main characteristics and fine conformational details of their structures are considered. © 2005 Russian Academy of Sciences and Turpion Ltd

Conformation of P(O)SCH3 and P (S) OSi (CH3)3 groups in 1,3,2-dioxaphospholanes

Based on the dipole moment data, either a cis or near-cis orientation of the phosphoryl and methyl groups, or of the thiophosphoryl and trimethylsilyl groups, is realized in the 2-oxo-2-methylthio- and the 2-thiono-2-trimethylsiloxy-4-methyl- and -4,5-dimethyl-1,3,2-dioxaphospholanes. © 1977 Plenum Publishing Corporation

Mechanism of the hydrolysis reactions of 1-hydroxysilatrane and 1-hydroxygermatrane, 2,2-dihydroxysilocane and 2,2-dihydroxygermocane

© 2016 Taylor & Francis Group, LLC.The mechanism of the hydrolysis reactions of 2,2-dihydroxysilocane, 2,2-dihydroxygermocane, 1-hydroxysilatrane, and 1-hydroxygermatrane was studied by the density functional theory method. According to the quantum chemical calculations, the reactions of hydrolysis for 2,2-dihydroxysilocane and 2,2-dihydroxygermocane are characterized by the lower values of activation energy than for 1-hydroxysilatrane and 1-hydroxygermatrane. The ring configurations of the hydrolysis products are stable due to the presence of transannular interaction N→X (X = Si, Ge) and intramolecular hydrogen bond in their molecules