THE REACTIVITY OF HYDROGEN ATOMS IN THE LIQUID PHASE. IV. THE REACTION WITH SOME HALOGENATED COMPOUNDS

1962 ◽  
Vol 66 (11) ◽  
pp. 2246-2249 ◽  
Author(s):  
T. J. Hardwick
Keyword(s):  
Liquid Phase ◽  
Halogenated Compounds ◽  
Hydrogen Atoms ◽  
Phase Iv

RADIATION CHEMISTRY OF CYCLOHEXANE: VI. DILUTE SOLUTIONS OF CARBON TETRACHLORIDE AND CHLOROFORM IN CYCLOHEXANE

1964 ◽  
Vol 42 (3) ◽  
pp. 669-681 ◽  
Author(s):  
J. A. Stone ◽  
P. J. Dyne
Keyword(s):  
Carbon Tetrachloride ◽  
Chemical Reaction ◽  
Physical Process ◽  
Radical Scavenging ◽  
Radiation Chemistry ◽  
Hydrogen Yield ◽  
Halogenated Compounds ◽  
Dilute Solutions ◽  
Hydrogen Atoms

A study of the effect of the addition of small amounts (<3.5%) of the halogenated compounds CCl4, CHCl3, and CDCl3 on the radiolysis of cyclohexane has shown that processes other than radical scavenging occur. At the lowest concentrations of solute that it was practical to employ (0.004 M) cyclohexyl radicals were scavenged without a corresponding reduction in the hydrogen yield. At higher solute concentrations G(H2) was reduced by a physical process which did not involve the scavenging of thermal hydrogen atoms but did lead to chemical reaction involving the solute.

60Co γ-RADIOLYSIS OF HYDROGEN HALIDES AT 77 °K

1966 ◽  
Vol 44 (2) ◽  
pp. 191-197
Author(s):  
R. C. Rumfeldt ◽  
D. A. Armstrong
Keyword(s):  
Liquid Phase ◽  
Hydrogen Atom ◽  
Experimental Error ◽  
Dose Dependence ◽  
Solid Matrix ◽  
Reactive Intermediate ◽  
Hydrogen Atoms ◽  
Hydrogen Halides ◽  
Atoms And Molecules ◽  
The Difference

Yields of hydrogen formed in the 60Co γ-radiolyses of pure polycrystalline samples of HBr and HCl at 77 °K decrease with increasing dose in the range 0 to 1 × 1018 eV per g. The true initial yields are G(H2)solidHClat77°K = 6.3 ± 0.2 and G(H2)solidHBrat77°K = 12.3 ± 0.3. Within experimental error these are the same as the respective liquid-phase yields at −79 °C. For doses in excess of 2 × 1018 eV per g the dose dependence is no longer significant and the yields tend toward plateau values of 3.2 ± 0.1 and 10.3 ± 0.1 for HCl and HBr respectively. The dose dependence of the hydrogen yields is attributed to the scavenging of a reactive intermediate by the halogen atoms and molecules which accumulate in the solid matrix as the dose increases.In independent experiments with an apparatus of the Klein–Scheer type it was shown that hydrogen atoms react readily with films of HBr at 77 °K. There is, however, no evidence of a significant reaction with HCl at this temperature. The difference in behavior of the two hydrogen halides may be explained by their different activation energies for reaction with hydrogen atoms. The results of the γ-radiolyses are discussed in the light of these experiments and it is suggested that the dose dependence may be a result of the scavenging of an ionic intermediate rather than a thermal hydrogen atom.

Structures and Solid-Liquid Phase Transition of High-Density Hydrogen Confined in Single-Walled Carbon Nanotubes

2009 ◽  
Vol 79-82 ◽  
pp. 67-70 ◽  
Author(s):  
Yue Yuan Xia ◽  
Ming Wen Zhao ◽  
Xiang Dong Liu ◽  
Yan Ju Ji
Keyword(s):  
Phase Transition ◽  
Carbon Nanotubes ◽  
Liquid Phase ◽  
Density Functional ◽  
Single Walled Carbon Nanotubes ◽  
Hydrogen Atoms ◽  
Liquid Phase Transition ◽  
Single Walled Carbon ◽  
Solid Liquid ◽  
Walled Carbon Nanotubes

Hydrogen with ultrahigh density confined in single-walled carbon nanotubes (SWCNTs) was investigated using density functional theory (DFT) and first principles molecular dynamics simulations (MDSs). Hydrogen atoms injected in to the cages of the SWCNTs via atomic collisions gradually form solid H2 molecular lattice with a characteristic of spiral multi-strands structure. The concentration of H2 confined in the SWCNTs can be as high as ~ 1.77×1023H2 /cm3, and the pressure between the H2 lattice and the wall of the SWCNT can be as high as ~ 77 GPa. When the system was heated to temperature higher than 700K, a solid-liquid phase transition was observed. When temperature rose to 1000K, a few H2 molecules dissociated forming a mixed liquid of H atoms, H2 molecules, and hydrogen trimers. Electron states near the Fermi level were appeared, which were attributed to the H atoms and the trimers. The electronic properties of the quasi-one-dimensional hydrogen confined in the SWNTs were thus substantially changed.

THE REACTIVITY OF HYDROGEN ATOMS IN THE LIQUID PHASE

1961 ◽  
Vol 65 (1) ◽  
pp. 101-108 ◽  
Author(s):  
Thomas J. Hardwick
Keyword(s):  
Liquid Phase ◽  
Hydrogen Atoms
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