Propriétés physiques et basicité de l'oxydipropionitrile

1984 ◽  
Vol 62 (2) ◽  
pp. 361-362 ◽  
Author(s):  
Jean-Claude Bollinger ◽  
Germaine Yvernault ◽  
Théophile Yvernault ◽  
Raymond Houriet
Keyword(s):  
Dielectric Constant ◽  
Refractive Index ◽  
Dipole Moment ◽  
Chemical Shift ◽  
Gas Phase ◽  
Solubility Parameter ◽  
Donor Number ◽  
Proton Chemical Shift ◽  
Acid Base ◽  
Propriétés Physiques

Physical constants (density, refractive index, viscosity, dielectric constant, dipole moment, solubility parameter) and some basicity parameters (donor number, proton chemical shift variation for CHCl3, gas phase basicity) have been determined for 3,3′-oxydipropionitrile (ODPN) at 25 °C. These results are compared with those for other usual solvents; they permit an explanation of its properties as a solvent for acid–base titrations, and the appearance of homohydrogen bonding in this medium.

Temperaturabhängigkeit der statischen Dielektrizitätskonstante und des optischen Brechungsindexes von Flüssigkeiten

1975 ◽  
Vol 30 (3) ◽  
pp. 287-291 ◽  
Author(s):  
I. Gryczyński ◽  
A. Kawski
Keyword(s):  
Dielectric Constant ◽  
Refractive Index ◽  
Dipole Moment ◽  
Dipole Moments ◽  
Mixed Solvents ◽  
Temperature Changes ◽  
Temperature Dependences ◽  
Solvent Shifts ◽  
Pure And Mixed Solvents ◽  
Good Agreement

A variation of the temperature changes the static dielectric constant (ε) and the refractive index (n) of solvents and, in conjunction with the measurement of solvent shifts of absorption and fluorescence maxima, allows the investigation of dipole moment changes of solutes in the excited state. For this purpose, investigations of the temperature dependences of ε and n of some pure and mixed solvents of different polarities have been made. It is found that the excited dipole moments of indole, 1,2-dimethylindole, 2,3-dimethylindole and tryptophan obtained from the shifts of the fluorescence maxima in mixed solvents at high temperatures are in good agreement with those obtained in other ways.

Concerning the role of the reaction field in the proton shielding of molecules in solution

1967 ◽  
Vol 45 (10) ◽  
pp. 1093-1096 ◽  
Author(s):  
G. Kotowycz ◽  
T. Schaefer
Keyword(s):  
Dielectric Constant ◽  
Chemical Shift ◽  
Solute Molecule ◽  
Proton Chemical Shift ◽  
Square Root ◽  
Reaction Field ◽  
Strong Curvature

It is shown that the strong curvature in some plots of proton chemical shift σ versus the Onsager reaction field E can be removed by plotting the shifts of the solute molecule versus the square root of the dielectric constant of the medium. The resulting values of k in the equation σ = −kE cos θ are fairly consistent and reasonable in magnitude.

The Oil Resistance of Rubber. II. Molecular Polarization and Dipole Moment of Purified Natural Rubber

1936 ◽  
Vol 9 (2) ◽  
pp. 296-300
Author(s):  
Shû Kambara
Keyword(s):  
Dielectric Constant ◽  
Refractive Index ◽  
Dipole Moment ◽  
Natural Rubber ◽  
Dipole Moments ◽  
Molecular State ◽  
True Value ◽  
Order Of Magnitude ◽  
Ether Solution ◽  
Constant Refractive Index

Abstract Natural rubber was purified by Pummerer's method and was dissolved in benzene and ether. The dielectric constant, refractive index, density, and concentration of the solutions were determined. From these data, the molecular polarization and dipole moment were calculated on the assumption that the rubber was dissolved in a molecular state of (C5H8)8. The dipole moments of total and gel rubber were found to be 2.45 and 2.91 × 10−18, respectively. These values are of the same order of magnitude as those of masticated crude rubber obtained by Ostwald. It may be said that the impurities of rubber are interlocked mechanically on the rubber molecule and are not combined chemically. Sol rubber in ether solution shows a far lower value than the values of total and gel rubber. These latter values may be influenced by autoöxidation, and the true value of the rubber hydrocarbon may be far smaller than the result described in this paper.

Solvents effects on the proton chemical shift and H—H, H—F coupling constants in 1-chloro-1-fluoroethylene. Reaction field and dispersion interactions

1967 ◽  
Vol 45 (10) ◽  
pp. 1111-1118 ◽  
Author(s):  
H. M. Hutton ◽  
T. Schaefer
Keyword(s):  
Dielectric Constant ◽  
Chemical Shift ◽  
Coupling Constants ◽  
Proton Chemical Shift ◽  
Coupling Constant ◽  
Dispersion Interactions ◽  
Proton Proton ◽  
Reaction Field ◽  
Proton Coupling ◽  
Solvent Molecules

The proton chemical shift and the geminal proton–proton and cis proton–fluorine coupling constants in 1-chloro-1-fluoroethylene depend primarily on the dielectric constant of the medium, although this dependence is not given by the Onsager reaction field model. A roughly linear relationship is found with the square root of the dielectric constant. The proton coupling constant decreases algebraically while the cis proton–fluorine coupling constant increases as the dielectric constant of the medium increases. The trans proton–fluorine coupling depends on dispersion interactions with the solvent molecules and increases as these interactions increase. The geminal coupling constant varies between − 3.8 and − 4.8 c.p.s., the cis coupling between 7.6 and 12.3 c.p.s., and the trans coupling between 36.9 and 38.6 c.p.s.

Sign in / Sign up

Export Citation Format

Share Document