An Infra-red spectroscopic study of naphthalene substitution

1955 ◽  
Vol 8 (3) ◽  
pp. 346 ◽  
Author(s):  
RL Werner ◽  
W Kennard ◽  
D Rayson
Keyword(s):  
Hydrogen Atom ◽  
Spectroscopic Study ◽  
Spectroscopic Data ◽  
Hydrogen Atoms ◽  
Naphthalene Derivatives ◽  
Bending Vibrations ◽  
Position Variable ◽  
Infra Red

Infra-red spectroscopic data on a number of mono- and disubstituted naphthalene derivatives have been obtained in the range 670-900 cm-l, in order to test the validity of the substitution rules based upon the hydrogen bending vibrations in this region and the number of adjacent hydrogen atoms in the molecules. It was found that the rules based on benzene substitution are generally valid for groups of two, three, or four hydrogen atoms in the naphthalene nucleus, although substituents which interact with the ring tend to widen the limits within which a band may be expected to fall. In the case of a single hydrogen atom the relevant bands are often weaker and their position variable.

Formation of surface layer of hydrogen in pure aluminum

2019 ◽  
Vol 484 (1) ◽  
pp. 56-60
Author(s):  
D. A. Indejtsev ◽  
E. V. Osipova
Keyword(s):  
Surface Layer ◽  
Hydrogen Atom ◽  
Ab Initio ◽  
Pure Aluminum ◽  
Hydrogen Atoms ◽  
Energy Characteristics ◽  
Aluminum Crystal

Hydrogen atom behavior in pure aluminum is described by ab initio modelling. All main energy characteristics of the system consisting of hydrogen atoms in a periodic aluminum crystal are found.

scholarly journals The photolysis of ammonia

1940 ◽  
Vol 175 (961) ◽  
pp. 187-207 ◽  
Keyword(s):  
Hydrogen Atom ◽  
Preceding Paper ◽  
Ammonia Molecule ◽  
Experimental Techniques ◽  
Hydrogen Atoms ◽  
Atom Concentration ◽  
Important Discrepancy

It has been shown in the preceding paper that the hypothesis that hydrazine is responsible for the anomalously low hydrogen atom concentration in the decomposition of ammonia must be abandoned. In order to explain this important discrepancy some new experimental techniques require to be developed which will settle the matter without appeal to further hypotheses. There are two general explanations of the discrepancy: (1) the hydrogen atoms are not produced as fast as that calculated on the assumption that every ammonia molecule absorbing a quantum necessarily decomposes, (2) that some entity not yet recognized removes hydrogen atoms at a rate faster than that at which they normally recombine. In this paper methods will be described in which these two problems are solved, and finally there is a discussion of the photochemistry of ammonia in the light of the new results obtained during these experiments.

scholarly journals Relationship between the Behavior of Hydrogen and Hydrogen Bubble Nucleation in Vanadium

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 322
Author(s):  
Zhengxiong Su ◽  
Sheng Wang ◽  
Chenyang Lu ◽  
Qing Peng
Keyword(s):  
Hydrogen Atom ◽  
First Principles ◽  
Bound States ◽  
Hydrogen Molecule ◽  
Vacancy Cluster ◽  
Bubble Nucleation ◽  
Hydrogen Bubble ◽  
First Principles Calculations ◽  
Hydrogen Atoms ◽  
Macroscopic Deformation

Hydrogen plays a significant role in the microstructure evolution and macroscopic deformation of materials, causing swelling and surface blistering to reduce service life. In the present work, the atomistic mechanisms of hydrogen bubble nucleation in vanadium were studied by first-principles calculations. The interstitial hydrogen atoms cannot form significant bound states with other hydrogen atoms in bulk vanadium, which explains the absence of hydrogen self-clustering from the experiments. To find the possible origin of hydrogen bubble in vanadium, we explored the minimum sizes of a vacancy cluster in vanadium for the formation of hydrogen molecule. We show that a freestanding hydrogen molecule can form and remain relatively stable in the center of a 54-hydrogen atom saturated 27-vacancy cluster.

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.

Photolyse du butène-1 dans l'ultraviolet à vide

1973 ◽  
Vol 51 (17) ◽  
pp. 2853-2859 ◽  
Author(s):  
Guy J. Collin
Keyword(s):  
Double Bond ◽  
Hydrogen Atom ◽  
Kinetic Energy ◽  
Thermal Energy ◽  
Hydrogen Atoms ◽  
Excited Molecules

The vacuum u.v. photolysis of 1 -butene was studied in the 147–105 nm region. The main products formed from the fragmentation of excited molecules are allene, 1,3-and 1,2-butadienes, ethylene, and acetylene. The addition of a hydrogen atom to the double bond produces mainly secondary butyl radicals (91%) at 147 nm. At 123.6 nm, this proportion becomes 82%. Thus at shorter wavelengths (10 and 11.6–11.8 eV), hydrogen atoms are produced with a kinetic energy higher than the thermal energy.

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