Radiolysis of Liquid Hydrocarbons: Dependence of the Free‐Ion Yield on Molecular Structure

1968 ◽  
Vol 49 (2) ◽  
pp. 954-955 ◽  
Author(s):  
P. H. Tewari ◽  
G. R. Freeman
Keyword(s):  
Molecular Structure ◽  
Liquid Hydrocarbons ◽  
Free Ion

Comparison between Molecular Structure Effects in Triplet Positronium Annihilation Rates and Radiolysis Free Ion Yields in Liquid Hydrocarbons

1972 ◽  
Vol 50 (16) ◽  
pp. 2697-2698 ◽  
Author(s):  
G. R. Freeman ◽  
J.-P. Dodelet
Keyword(s):  
Molecular Structure ◽  
Chain Length ◽  
Molecular Interaction ◽  
Half Life ◽  
Density Effect ◽  
Liquid Hydrocarbons ◽  
Positronium Annihilation ◽  
Free Ion ◽  
Alkane Chain ◽  
Ion Yields

Two seemingly unrelated phenomena in liquid hydrocarbons have similar trends in their dependences upon the molecular structure of the hydrocarbon. The phenomena are the annihilation half-life of triplet positronium and the radiolysis free ion yield. In n-alkanes the effect of increasing the molecular chain length, upon both phenomena, appears to be simply to increase the density of interacting sites. Branching the alkane chain decreases the strength of molecular interaction with both electrons and positronium, although the relative decrease is much greater for the former than for the latter. The effects of double bonds on the phenomena, after separating out the density effect, are different from each other.

Yields of Free Ions in the X Radiolysis of Some Simple Saturated and Unsaturated Hydrocarbon Liquids: Effects of Molecular Structure and Temperature

1971 ◽  
Vol 49 (22) ◽  
pp. 3657-3664 ◽  
Author(s):  
M. G. Robinson ◽  
P. G. Fuochi ◽  
G. R. Freeman
Keyword(s):  
Molecular Structure ◽  
Interaction Model ◽  
Unsaturated Hydrocarbon ◽  
The Other ◽  
Coulombic Interaction ◽  
Secondary Electrons ◽  
Free Ions ◽  
Free Ion ◽  
Liquid Methane ◽  
Hydrocarbon Molecules

Pulse techniques were used at temperatures ranging from 120 to 293 °K. A quasifree electron conductance transient (k/u overshoot) was observed in liquid methane, but not in ethane, propane, cyclopropane, ethylene, propylene or butene-1. The free ion yield in methane, Gfi = 0.8 at 120 °K, is much larger than those in the other liquids, which at 183°K are: ethane, 0.13; propane, 0.076; cyclopropane, 0.04; ethylene, 0.017; propylene, 0.04; butene-1, 0.027. The activation energies of free ion formation are, in kcal/mol: ethane, 0.6; propane, 0.8; ethylene, 0.5; propylene, 1.0; butene-1, 1.0. The results are interpreted in terms of the coulombic interaction model. The distances that the secondary electrons penetrate the liquid away from their parent ions are greater when the hydrocarbon molecules are more sphere-like, and are reduced by the presence of a π bond in the molecule. Cyclopropane behaves somewhat like an olefin in this regard, a fact that is explained by the unusual bonding in the C3 ring. In the present liquids the only ionization events that contribute appreciably to the free ion yield are those in which the electron penetrates [Formula: see text] from the parent ion.

Towards the Positronium and Radiolytic Hydrogen Formation Mechanisms in Liquid Hydrocarbons

2012 ◽  
Vol 733 ◽  
pp. 19-23
Author(s):  
Vsevolod Byakov ◽  
Sergey V. Stepanov
Keyword(s):  
Molecular Structure ◽  
Radical Cations ◽  
Formation Mechanisms ◽  
Cyclic Form ◽  
Liquid Hydrocarbons ◽  
Hydrogen Formation ◽  
Saturated Hydrocarbons ◽  
Cyclic Hydrocarbons ◽  
Primary Radical ◽  
Structure Changes

Ps and radiolytic hydrogen yields anticorrelate in saturated hydrocarbons when molecular structure changes from a normal to a cyclic form. This fact is explained by much higher mobility of primary radical-cations in cyclic hydrocarbons than in normal ones.

Influence of Molecular Structure upon the Electric Strengths of Liquid Hydrocarbons

1956 ◽  
Vol 27 (7) ◽  
pp. 806-808 ◽  
Author(s):  
A. H. Sharbaugh ◽  
R. W. Crowe ◽  
E. B. Cox
Keyword(s):  
Molecular Structure ◽  
Liquid Hydrocarbons

Electron mobility in nonpolar liquids: the effect of molecular structure, temperature, and electric field

1977 ◽  
Vol 55 (11) ◽  
pp. 2197-2210 ◽  
Author(s):  
Werner F. Schmidt
Keyword(s):  
Molecular Structure ◽  
Electric Field ◽  
High Mobility ◽  
Liquid Hydrocarbons ◽  
Limited Temperature ◽  
Excess Electrons ◽  
Liquid Methane ◽  
Nonpolar Liquids ◽  
Electron Models ◽  
Related Compounds

A survey is given on the mobility of excess electrons in liquid hydrocarbons and related compounds. It was found that the mobility is strongly influenced by the molecular structure of the liquid, by the temperature, and by the electric field strength. The mobility in hydrocarbons increases as the shape of the molecule approaches a sphere. The temperature coefficient is positive in most liquids over a limited temperature although exceptions have been observed in liquid methane. The field dependence of the mobility in high mobility liquids (>10 cm2V−1s−1) showed a decrease of the mobility at higher field strengths while in low mobility liquids (<1 cm2V−1s−1) it showed an increase. These results are discussed on the basis of the extended and the localized electron models. The predictions of these theories are compared with the experimental results and conclusions on the validity of the underlying assumptions are drawn.

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