Low-Frequency Dielectric Absorption in Organic Long-Chain Compounds due to the Presence of Traces of Alcohol Impurities

Nature ◽  
1950 ◽  
Vol 166 (4209) ◽  
pp. 29-30 ◽  
Author(s):  
B. V. HAMON ◽  
R. J. MEAKINS
Keyword(s):  
Low Frequency ◽  
Dielectric Absorption ◽  
Chain Compounds ◽  
Long Chain

Polytypic structure and low-frequency Raman spectra of long-chain compounds: Stearic acid E form

1993 ◽  
Vol 24 (8) ◽  
pp. 527-532 ◽  
Author(s):  
Fumitoshi Kaneko ◽  
Masamichi Kobayashi ◽  
Hirotoshi Sakashita
Keyword(s):  
Stearic Acid ◽  
Raman Spectra ◽  
Low Frequency ◽  
Chain Compounds ◽  
Long Chain

The Dielectric Properties of a Series of dl-n-Eicosanols

1951 ◽  
Vol 4 (3) ◽  
pp. 359
Author(s):  
RJ Meakins ◽  
HK Welsh
Keyword(s):  
Dielectric Properties ◽  
Low Frequency ◽  
Polar Compounds ◽  
Carbon Chain ◽  
Hydroxyl Groups ◽  
Secondary Alcohols ◽  
Polar Group ◽  
Dielectric Absorption ◽  
Ready Availability ◽  
Long Chain

Initial investigations of the dielectric properties of normal long-chain secondary alcohols were made with the symmetrical compounds because of their ready availability. The properties of long-chain polar compounds are known to vary considerably, however, with the position of the polar group in the carbon chain and it therefore seemed desirable to make dielectric measurements with some unsymmetrical alcohols. The present paper describes such an investigation of a series of dl-n-eicosanols having the hydroxyl groups in the 2-, 4-, 6-, 8-, and 10-positions, respectively. The results for the melted forms show that slight asymmetry, as in the 10-compound, has little effect on the dielectric properties, but with the more unsymmetrical 4-, 6-, and 8-compounds a considerable enhancement of the dielectric absorption is observed. This is accompanied by increased dispersion of the dielectric constant which, for the 8-compound, reaches a low frequency value of 15. Both ε" and ε' decrease during storage at room temperature. Anomalous results are obtained with dl-n-eicosan-2-ol, probably due to the molecules in the crystal lattice being alternately reversed, end-to-end. As with the symmetrical secondary alcohols, the recrystallized forms give comparatively little dielectric absorption.

scholarly journals Stereospecific Hydroxylation of Long Chain Compounds by a Species of Torulopsis

1969 ◽  
Vol 244 (4) ◽  
pp. 882-888 ◽  
Author(s):  
E Heinz ◽  
A P Tulloch ◽  
J F T Spencer
Keyword(s):  
Chain Compounds ◽  
Long Chain

Excess heat capacities and excess volumes of tetraalkyltin compounds: . Effect of correlations of molecular orientations and steric hindrance. Part 1

1984 ◽  
Vol 62 (6) ◽  
pp. 1008-1015 ◽  
Author(s):  
Bernard Riedl ◽  
Geneviève Delmas
Keyword(s):  
Steric Hindrance ◽  
Central Atom ◽  
Orientational Order ◽  
Excess Volumes ◽  
Pure Liquid ◽  
Flory Theory ◽  
Flow Calorimeter ◽  
Alkyl Chains ◽  
Chain Compounds ◽  
Long Chain

A Picker flow calorimeter has been used to obtain molar excess capacities [Formula: see text] through the concentration range at 25 °C for the systems [Formula: see text] where R is the alkyl group CnH2n+1, (n = 1, 2, 3, 4, 8, 12). Excess volumes have also been measured for the mixtures. Two contributions to [Formula: see text] and vE were investigated: those associated with disordering the long alkyl chains and with steric hindrance. The steric hindrance contribution has been found to occur for molecules having a highly substituted central atom. The sign of this contribution is negative in hE and positive in [Formula: see text], indicative of an ordering or loss of mobility for the molecules going from pure liquid to solution. The [Formula: see text] results confirm the more sterically hindered character of the ethyl and propyl derivatives already found with hE. The separation of the disorder and steric contribution is possible in systems involving long-chain compounds. It is found that the orientational order contribution diminishes more slowly with temperature than the steric hindrance effect. The trend of vE in the series is reasonably well predicted by the Prigogine–Patterson–Flory theory.

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