scholarly journals Atomic polarization in metal chelates. II. Dielectric loss measurements on some diketone chelates of tin(IV)

1973 ◽  
Vol 26 (4) ◽  
pp. 871 ◽  
Author(s):  
JW Hayes ◽  
WH Nelson ◽  
DV Radford
Keyword(s):  
Dielectric Loss ◽  
Dipole Moments ◽  
Relaxation Times ◽  
Metal Chelates ◽  
Atomic Polarization ◽  
Orientation Polarization

Dipole moments and relaxation times determined by dielectric loss measurements at 3.109 and 9.400 GHz are reported for bis(pentane-2,4- dionato)dimethyltin(IV) and its dimethyl and diphenyl analogues with tropolone. All of these compounds show true orientation polarization in accord with the assignment of cis structures. High atomic polarizations are observed in all cases and it is suggested that this may be a characteristic of metal chelates in general.

Dielectric loss measurements for Bis(pentane-2,4-dionato)oxovanadium(IV) in benzene and dioxan

1975 ◽  
Vol 28 (5) ◽  
pp. 1137 ◽  
Author(s):  
MJ Aroney ◽  
RL Angel
Keyword(s):  
Dielectric Loss ◽  
Complex Formation ◽  
Dielectric Relaxation ◽  
Dipole Moments ◽  
Relaxation Times

Dipole moments and dielectric relaxation times determined by dielectric loss measurements are reported for bis(pentane-2,4- dionato)oxovanadium(IV) as a solute in benzene and in dioxan. Evidence is presented for VO(acac)2,dioxan complex formation.

scholarly journals Dielectric constant and induced dipole moment of edible oils subjected to conventional heating

2012 ◽  
Vol 31 (2) ◽  
pp. 285 ◽  
Author(s):  
Margareta Pecovska Gjorgjevich ◽  
Aleksandar Andonovski ◽  
Julijana Velevska
Keyword(s):  
Dielectric Constant ◽  
Dielectric Loss ◽  
Corn Oil ◽  
Edible Oils ◽  
Dipole Moments ◽  
Virgin Olive Oil ◽  
Peak Frequency ◽  
Conventional Heating ◽  
Orientation Polarization ◽  
Induced Dipole

The frequency dependence of dielectric constant, dielectric loss factor and conductivity are studied for five edible oils in the frequency range 100 kHz to 13 MHz at different temperatures using frequency domain spectroscopy. The dielectric constant is found similar for all the samples and in agreement with the previous reports. The dielectric loss is low (<0.01) except for the virgin olive oil with value of 0.05. Dielectric loss peak frequency is at  4 MHz for corn oil and around 5.2 MHz for the others. At this frequency conductivity is of the order of 10-7-10-9 S/cm, and decreases with temperature following the behavior of the dielectric losses. Refractive index, molar and orientation polarization are calculated for all types of oils using novel theory proposed by N. M. Putintsev and D. N. Putintsev [1]. Data show that the orientation polarization contributes to the observed dielectric constant at low temperatures and frequencies.  This indicates that the edible oils are not pure nonpolar dielectrics. Induced dipole moments of oils are calculated for 400 kHz and 10 MHz at 300 K and 318 K. The results are discussed and correlated as a function of temperature and frequency to establish their relationship.

Main Dielectric Dispersion Region of Mixtures of some Long-Chain Alcohols with Non-Polar Solvents

1972 ◽  
Vol 27 (8-9) ◽  
pp. 1363-1367 ◽  
Author(s):  
F. F. Hanna ◽  
I. K. Hakim
Keyword(s):  
Dielectric Constant ◽  
Dielectric Loss ◽  
Dipole Moments ◽  
Relaxation Times ◽  
Dielectric Dispersion ◽  
Concentrated Solutions ◽  
Polar Solvents ◽  
Dispersion Region ◽  
Long Chain

Abstract The dielectric constant ε' and dielectric loss ε" are measured for concentrated solutions of n-dodecanol and n-octanol with five non-polar solvents at five frequencies between 2 and 400 MHz at three temperatures between 20 and 60 °C. The effective dipole moments have been calculated and found to decrease with increasing dilution. The relaxation times of the concentrated solutions are lower than that of the pure alcohols, decrease with dilution and are dependent on the nature of the non-polar solvents.

DIELECTRIC RELAXATION IN COMPLEX PEROVSKITE BaFe1/2Sb1/2O3

2007 ◽  
Vol 21 (17) ◽  
pp. 2965-2978 ◽  
Author(s):  
A. DUTTA ◽  
T. P. SINHA
Keyword(s):  
Dielectric Loss ◽  
Electric Modulus ◽  
Relaxation Times ◽  
Scaling Behavior ◽  
Perovskite Oxide ◽  
X Ray Diffraction ◽  
Complex Perovskite ◽  
Relaxation Parameters ◽  
Iron Antimonate ◽  
First Time

The complex perovskite oxide barium iron antimonate, BaFe 1/2 Sb 1/2 O 3 (BFS) is synthesized by a solid-state reaction technique for the first time. The X-ray diffraction of the sample at room temperature shows a monoclinic phase. The field dependences of dielectric response and the loss tangent of the sample are measured in a frequency range from 50 Hz to 1 MHz and in a temperature range from 143 to 463 K. An analysis of the loss factor with frequency is performed by the scaling behavior of the dielectric loss spectra. The frequency dependence of the loss peaks are found to obey the Arrhenius law with an activation energy ≃0.81 eV . The scaling behavior of the dielectric loss spectra suggests that the distribution of relaxation times is temperature-independent. The frequency-dependent electrical data are also analyzed in the framework of conductivity and electric modulus formalisms. The scaling behavior of the imaginary electric modulus shows the temperature-independent nature of the distribution of relaxation times. All these formalisms resulted in the qualitative similarities in the relaxation time. The relationship between relaxation parameters and electrical conduction indicates the hopping motion of electrons from Fe(II) to Fe(III) ions in BFS.

Microwave Relaxation and Association of 3,5 Dimethyl 3-Hexanol

1970 ◽  
Vol 25 (11) ◽  
pp. 1685-1687
Author(s):  
F. F. Hanna ◽  
K. N. Abd-El-Nour
Keyword(s):  
Dielectric Constant ◽  
Relaxation Time ◽  
Dielectric Loss ◽  
Relaxation Times ◽  
Concentrated Solutions ◽  
Short Relaxation Time

Abstract The dielectric constant (ε′) and dielectric loss (ε′′) of 3,5 dimethyl 3-hexanol in heptane have been measured for dilute and concentrated solutions at five wavelengths between 25 cm and 2 mm and at 20°, 40° and 60 °C. The data have been analysed and two relaxation times are obtained. The long relaxation time is attributed to the rotation of the whole molecule and the short relaxation time to the relaxation of the OH-group. For the range of concentrations used, the results show that associates are hardly detectable.

Polarization and apparent dipole moments of some symmetrical molecules

1991 ◽  
Vol 56 (2) ◽  
pp. 406-410 ◽  
Author(s):  
Otto Exner ◽  
Ivan Mach
Keyword(s):  
Complex Formation ◽  
Standard Method ◽  
Dipole Moments ◽  
The Other ◽  
Atomic Polarization ◽  
Other Hand ◽  
Unknown Structure ◽  
Apparent Orientation

Polarization and apparent dipole moments of a series of symmetrical molecules were determined by the standard method in three solvents: benzene, p-xylene, and mesitylene. Their explanation by complex formation with solvent applies only in the case of 1,4-dicyanobenzene and 4,4’-dicyanobiphenyl since the apparent orientation polarizations (PO.app) are large and depend strongly on solvent. On the other hand, 1,4-dihalogenbenzenes do not form any complexes and PO.appis virtually zero. 1,4-Dihalogenbicyclo[2,2,2]octanes reveal also considerable PO.app which is attributed mainly to enhanced atomic polarization but – in the case of heavier halogens – also partly to complexes of unknown structure.

The solution dipole moments and the atomic polarizations of chloro-, bromo-, and iodo-benzenes

1968 ◽  
Vol 21 (7) ◽  
pp. 1721 ◽  
Author(s):  
HH Huang ◽  
VR Sullivan
Keyword(s):  
Dielectric Constant ◽  
Carbon Tetrachloride ◽  
Dipole Moments ◽  
Quantitative Information ◽  
Atomic Polarization ◽  
Density Measurements ◽  
Polar Solutes

Dielectric constant and density measurements of solutions of chloro-, bromo-, and iodo-benzene together with those of p-dichloro-, p-dibromo- and p-diiodo-benzene in carbon tetrachloride at 25� are given. Distortion and atomic polarization values for the polar solutes are estimated by a method proposed by B�ttcher; the values are compared with other estimates of PD and PA. To obtain quantitative information of atomic polarizations, using B�ttcher's method, greater precision than is usual in solution dielectric constant measurements would be required.

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