Dipole moment studies of some derivatives of 4-pyridone

1972 ◽  
Vol 25 (12) ◽  
pp. 2605 ◽  
Author(s):  
BD Batts ◽  
AJ Madeley
Keyword(s):  
Dipole Moment ◽  
Dipole Moments ◽  
Phenyl Group ◽  
A Value ◽  
Derivatives Of

The dipole moments of 13 derivatives of 4-pyridone were measured. Attempts to obtain a value for 4-pyridone were unsuccessful but a value of 6.O D is compatible with other evidence. Dipole moment and n.m.r, evidence indicated that for N-phenyl-4-pyridone the phenyl group is inductively electron-repelling (in contrast to that reported)1,2 for N-phenylpyrrole) and that the rings are probably collinear.

Determination of dipole moment values of anisotropic molecules using Brot's formalism

1990 ◽  
Vol 68 (9) ◽  
pp. 1523-1526
Author(s):  
P. Brito ◽  
M. Mechetti
Keyword(s):  
Molecular Structure ◽  
Dipole Moment ◽  
Dipole Moments ◽  
Dilute Solutions ◽  
Molecular Anisotropy ◽  
Derivatives Of ◽  
Best Parameters

A method for the determination of dipole moment values based on Brot's theory is proposed. It takes into account the influence of the molecular anisotropies of shape and polarizability on the permittivity of a mixture. Starting from measurements performed on dilute solutions and from the knowledge of the molecular structure of some chlorinated derivatives of α-cyanostilbene and 1,3 derivatives of benzene, the best parameters of an ellipsoid used for the representation of a polar anisotropic molecule are determined. The dipole moments obtained, using benzene and tetrachloromethane as solvents, are finally compared to values from the literature. Keywords: dipole moment, Brot's formalism, molecular anisotropy.

Conformation around several equivalent bonds. Polymethoxy derivatives of benzene

1983 ◽  
Vol 48 (4) ◽  
pp. 1030-1041 ◽  
Author(s):  
Otto Exner ◽  
Václav Jehlička
Keyword(s):  
Dipole Moment ◽  
Crystalline Phase ◽  
Benzene Solution ◽  
Dipole Moments ◽  
Graphical Comparison ◽  
Methoxy Groups ◽  
Derivatives Of

Dipole moments of benzene methoxy derivatives I-IX were measured in benzene solution and discussed in terms of the conformation around the Car-O bonds, exploiting the method of graphical comparison and systematic introduction of substituents. In the case of 1,2-dimethoxybenzene several explanations are in accord with the dipole moment data. However, considering all available evidence, most probable seems to be the presence of two conformers, one of which is non-planar with two non-equivalent methoxy groups (IC). The conformation of 1,2,3-trimethoxybenzene is similar to that found for many derivatives in the crystalline phase (VC), only the outer methoxy groups are probably slightly deviating from the coplanar position.

Three-membered Rings. Molecular Structure and Conformation of Aryl Substituted Oxiranes by Dipole Moment Measurements

1977 ◽  
Vol 32 (12) ◽  
pp. 1467-1472 ◽  
Author(s):  
Salvatore Sorriso ◽  
Carlo Battistini ◽  
Bruno Macchia ◽  
Franco Macchia
Keyword(s):  
Molecular Structure ◽  
Dipole Moment ◽  
Electric Dipole ◽  
Dipole Moments ◽  
Phenyl Group ◽  
Electric Dipole Moments ◽  
Bond Angles ◽  
Styrene Derivatives

The electric dipole moments of some styrene and trans- and cis-stilbene oxides have been measured, in benzene. From these data some bond angles have been calculated and it has been deduced that in the styrene derivatives the phenyl group is in rapid interconversion about the bond with the triatomic ring.

scholarly journals An analysis of the dipole moments of some aromatic compounds

1934 ◽  
Vol 145 (854) ◽  
pp. 71-80 ◽  
Keyword(s):  
Dipole Moment ◽  
Aromatic Compounds ◽  
General Type ◽  
Dipole Moments ◽  
Aromatic Nucleus ◽  
Organic Substances ◽  
Benzene Derivatives ◽  
Electronic Theory ◽  
Disubstituted Benzene ◽  
Derivatives Of

The dipole moments of organic substances represent the resultants of a number of distinct moments within the molecule form which they must, as was pointed out by Sir J. J. Thomson, be obtainable by vector summation. This view was extended and further examined by Eucken and Meyer in 1929. It has been generally accepted and confirmed for a large variety of substances. The figures for para -disubstituted benzene derivatives of the type X. C 6 H 4 . Y are of particular importance for two reasons. First, it was anticipated by Ingold on the ground of the electronic theory of aromatic reactivity, that some deviation from the additive law might occur in this class of compound when Y was a group such as —NR 2 as a result of electronic displacements in the aromatic nucleus. When the necessary data became available by the measurements of Højendahl, a gross discrepancy of this kind appeared probable for p -nitraniline and p -nitroanisole, and this was specifically emphasized at that time. Secondly, a number of workers have recently made use of dipole moment data for aromatic ethers and sulphides of this same general type in order to compute the angle between the valencies of the characteristic atom (oxygen and sulphur) of the group Y.

Charge Distribution Within 1,2-Dicarba-closo-dodecaborane: Dipole Moments of Its Phenyl Derivatives

2001 ◽  
Vol 66 (9) ◽  
pp. 1375-1379 ◽  
Author(s):  
Drahomír Hnyk ◽  
Václav Všetečka ◽  
Ladislav Drož ◽  
Otto Exner
Keyword(s):  
Dipole Moment ◽  
Charge Distribution ◽  
Electron Acceptor ◽  
Dipole Moments ◽  
Phenyl Group ◽  
Weak Electron

The dipole moment of 1,2-dicarba-closo-dodecaborane is oriented with the positive end towards the carbon atoms as follows from measurements on phenyl derivatives with variable substituents. Towards the phenyl group, the substituent 1,2-C2B10H11 behaves as a weak electron acceptor.

Etude de l'équilibre dans les oxazolo[2,3-e], thiazolo[2,3-e] et isoxazolo[2,3-d]tétrazoles. II. Etude de l'effet de la température par dipolemetrie et résonance magnétique nucléaire

1977 ◽  
Vol 55 (10) ◽  
pp. 1728-1735 ◽  
Author(s):  
Robert Faure ◽  
Jean-Pierre Galy ◽  
Emile-Jean Vincent ◽  
Jean-Pierre Fayet ◽  
Pierre Mauret ◽  
...  
Keyword(s):  
Dipole Moment ◽  
Equilibrium Constant ◽  
Dipole Moments ◽  
Equilibrium Constants ◽  
Proton Nmr ◽  
Photoelectron Spectra ◽  
A Value ◽  
Résonance Magnétique ◽  
Entropy Factor

The equilibrium constant in dioxane between azido and tétrazole isomers has been obtained for five heterocyclic azides (2-azido thiazoles, benzothiazole, benzoxazole, and 3-azido isoxazole) by proton nmr and dipole moment- studies. The last method involves a comparison between experimental and calculated (INDO, CNDO/2, CNDO/S) dipole moments. The CNDO/S method gives the best equilibrium constants and entropy factor (ΔS ∼ 50 J K−1 mol−1). A value of 114° for the C—N—N angle is found to account satisfactorily for certain properties (energy, dipole moment, photoelectron spectra) of aromatic azides. The heterocyclic azidoimines prefer the Z conformation.

Excited States Dipole Moments and Fluorescence Behaviour of Some Derivatives of Dimethylaminobenzonitrile

1990 ◽  
Vol 45 (7) ◽  
pp. 883-888
Author(s):  
C. Brittinger ◽  
A. K. Maiti ◽  
W. Baumann ◽  
N. Detzer
Keyword(s):  
Dipole Moment ◽  
Excited State ◽  
Charge Transfer ◽  
Excited States ◽  
Intramolecular Charge Transfer ◽  
Dipole Moments ◽  
Solvent Polarity ◽  
Polar Solvents ◽  
Derivatives Of ◽  
Limiting Value

AbstractTwo sterically hindered derivatives of dimethylaminobenzonitrile (DMCA) have been synthesized and the dipole moment of their fluorescent excited state has been determined in differently polar solvents. Its value increases with solvent polarity up to a limiting value of (50 + 2.5) • 10-30 Cm. The results are discussed with reference to the twisted intramolecular charge transfer (TICT) state formation in the class of molecules related to DMCA.

Infrared spectra and substituent effects in 2-(3-, and 4-substituted phenylmethylene)-1,3-cycloheptanediones

1983 ◽  
Vol 48 (2) ◽  
pp. 586-595 ◽  
Author(s):  
Alexander Perjéssy ◽  
Pavol Hrnčiar ◽  
Ján Šraga
Keyword(s):  
Substituent Effects ◽  
Phenyl Group ◽  
Wave Number ◽  
Vibrational Coupling ◽  
Wave Numbers ◽  
Stretching Vibration ◽  
Stretching Vibrations ◽  
The Relationship ◽  
Derivatives Of ◽  
Effect Of Structure

The wave numbers of the fundamental C=O and C=C stretching vibrations, as well as that of the first overtone of C=O stretching vibration of 2-(3-, and 4-substituted phenylmethylene)-1,3-cycloheptanediones and 1,3-cycloheptanedione were measured in tetrachloromethane and chloroform. The spectral data were correlated with σ+ constants of substituents attached to phenyl group and with wave number shifts of the C=O stretching vibration of substituted acetophenones. The slope of the linear dependence ν vs ν+ of the C=C stretching vibration of the ethylenic group was found to be more than two times higher than that of the analogous correlation of the C=O stretching vibration. Positive values of anharmonicity for asymmetric C=O stretching vibration can be considered as an evidence of the vibrational coupling in a cyclic 1,3-dicarbonyl system similarly, as with derivatives of 1,3-indanedione. The relationship between the wave numbers of the symmetric and asymmetric C=O stretching vibrations indicates that the effect of structure upon both vibrations is symmetric. The vibrational coupling in 1,3-cycloheptanediones and the application of Seth-Paul-Van-Duyse equation is discussed in relation to analogous results obtained for other cyclic 1,3-dicarbonyl compounds.

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