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.

Photolyse de pentène-1 dans l'ultraviolet à vide

1973 ◽  
Vol 51 (5) ◽  
pp. 724-731 ◽  
Author(s):  
Patrick M. Perrin ◽  
Guy J. Collin
Keyword(s):  
Double Bond ◽  
Low Pressure ◽  
Hydrogen Atoms ◽  
Ethyl Radical ◽  
Excited Molecules

Photolysis of 1-pentene molecules at 8.4 eV (xenon photolysis) and 10.0 eV (krypton photolysis) was studied. Excited molecules decompose to produce mainly ethylene, propadiene, 1,3-butadiene, acetylene, and other minor products. Hydrogen atoms add to the double bond of the monomer and the resulting excited pentyl radical decomposes at low pressure (P < 1 Torr) into propene and ethyl radical. Isomerization of excited 1-pentene molecules is unimportant at these energies.

Reactions of vibrationally excited molecules. I. The reaction of methylene with iso butene

1959 ◽  
Vol 250 (1262) ◽  
pp. 409-421 ◽  
Keyword(s):  
Double Bond ◽  
Kinetic Energy ◽  
Hydrogen Bonds ◽  
Excess Energy ◽  
Vibrationally Excited ◽  
Carbon Double Bond ◽  
Sufficient Energy ◽  
Carbon Hydrogen Bonds ◽  
Excited Molecules

The photolysis of diazomethane in the presence of iso butene has been investigated. The results obtained are explained on the basis that the methylene initially produced may be vibrationally excited, to an extent which depends on the wavelength of the radiation employed in the photolysis, and may also contain considerable kinetic energy. The methylene resets before this excess energy is lost, attacking the carbon hydrogen bonds and carbon carbon double bond in iso butene. The latter attack yields 1.1 -dimethyl cyclo Zopropane which contains sufficient energy to isomerize, and does so, unless stabilized by collision. The results obtained are compared with those published for the photolysis of keten in the presence of iso butene.

scholarly journals Elliptically polarized laser assisted elastic electron-hydrogen atom collision and differential scattering cross-section

2020 ◽  
pp. 93-102
Author(s):  
Kishori Yadav ◽  
S.P. Gupta ◽  
J.J. Nakarmi
Keyword(s):  
Hydrogen Atom ◽  
Kinetic Energy ◽  
Cross Section ◽  
Laser Field ◽  
High Energy ◽  
Scattering Cross Section ◽  
Hydrogen Atoms ◽  
Differential Scattering Cross Section ◽  
Scattering Cross ◽  
Cross Section Area

In the present study, we have investigated scattering of an electron by hydrogen atoms in the presence of the elliptical polarized laser field. We have discussed the polarization effect of laser field on hydrogen atom and effect of the resulted polarized potential on differential scattering cross-section is studied. We assume the scattered electrons having kinetic energy (~3000 eV) and laser field of moderate field strength because it is permitted to treat the scattering process in first Born approximation and the scattering electron was described by Volkov wave function. We found that the differential scattering cross-section area increases with the increase of the kinetic energy of the incident electron and there is no effect of changing the value of polarizing angle on the differential cross-section with kinetic energy. We observed that differential scattering cross-section in elliptical polarization in the high energy region depends upon the laser intensity and the incident energy for a linearly polarized field.

The kinetics of the interaction of atomic hydrogen with olefines. V. Results obtained for a further series of compounds

1950 ◽  
Vol 202 (1069) ◽  
pp. 181-202 ◽  
Keyword(s):  
Double Bond ◽  
Hydrogen Atom ◽  
Atomic Hydrogen ◽  
Methyl Radicals ◽  
Hydrogen Atoms ◽  
Alkyl Radicals ◽  
Kinetics Of ◽  
Interesting Generalization

In this paper the efficiency of interaction of a hydrogen atom with a series of olefines has been determined, the olefines being members of the series obtained by progressively replacing the hydrogen atoms of ethylene by methyl radicals. The interesting generalization which emerges from this is that the efficiency of interaction does not vary very much with the nature of the alkyl substituents in the molecule, and calculations involving the heats of addition of a hydrogen atom to a double bond confirm this generalization. The data presented here are discussed critically in relation to information available on the reaction of CCl 3 radicals with olefines and of alkyl radicals with olefines, complete general agreement being demonstrated.

Reactions of vibrationally excited molecules II. The reaction of methylene with trans and cis butene-2

1959 ◽  
Vol 251 (1267) ◽  
pp. 575-587 ◽  
Keyword(s):  
Double Bond ◽  
Kinetic Energy ◽  
Excess Energy ◽  
Vibrationally Excited ◽  
Geometrical Isomerization ◽  
Considerable Excess ◽  
Structural Isomerization ◽  
Excited Molecules

The photolysis of diazomethane in the presence of trans butene -2 and cis butene -2 has been investigated. The results are explained on the basis that the methylene initially produced may be vibrationally excited, and may also contain considerable excess kinetic energy. The methylene reacts with the butenes before this excess energy is lost. The trans and cis 1 .2-dimethylq/cZopropanes produced by the add tion of the methylene to the double bond in trans and cis butene-2, respectively, undergo both geometrical and structural isomerization unless collisionally stabilized. The structural isomerization, which is considerably slower than the geometrical isomerization, results in the formation of cis and trans pentene-2,2-m ethylbutene-2 and 2 -m ethylbutene-l

scholarly journals The conversion of cholest-7-en-3β-ol into cholesterol. General comments on the mechanism of the introduction of double bonds in enzymic reactions

1967 ◽  
Vol 105 (3) ◽  
pp. 1187-1194 ◽  
Author(s):  
S. Marsh Dewhurst ◽  
M Akhtar
Keyword(s):  
Double Bond ◽  
Hydrogen Atom ◽  
Experimental Evidence ◽  
Double Bonds ◽  
Anaerobic Conditions ◽  
Hydrogen Atoms ◽  
Aerobic Conditions ◽  
Metabolic Studies ◽  
Hypothetical Mechanism ◽  
Dehydration Mechanism

Convenient syntheses of 6β-tritiated Δ7-cholestenol and 3α-tritiated Δ7-cholestene-3β,5α-diol are described. It was shown that the conversion of 6β-tritiated Δ7-cholestenol into cholesterol is accompanied by the complete retention of label. It was unambiguously established that the overall reaction leading to the introduction of the double bond in the 5,6-position in cholesterol occurs via a cis-elimination involving the 5α- and 6α-hydrogen atoms and that during this process the 6β-hydrogen atom remains completely undisturbed. Metabolic studies with 3α-tritiated Δ7-cholestene-3β,5α-diol revealed that under anaerobic conditions the compound is not converted into cholesterol. This observation, coupled with the previous work of Slaytor & Bloch (1965), is interpreted to exclude a hydroxylation–dehydration mechanism for the origin of the 5,6-double bond in cholesterol. It was also shown that under aerobic conditions 3α-tritiated Δ7-cholestene-3β,5α-diol is efficiently converted into cholesterol and that this conversion occurs through the intermediacy of 7-dehydrocholesterol. Cumulative experimental evidence presented in this paper and elsewhere is used to suggest that the 5,6-double bond in cholesterol originates through an oxygen-dependent dehydrogenation process and a hypothetical mechanism for this and related reactions is outlined.

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.

DEVELOPMENT OF CONSTRUCTION OF THREE-INPUT GENERATING INSTALLATIONS ON BASED OF RENEWABLE ENERGY SOURCES

2018 ◽  
Author(s):  
Я.М. КАШИН ◽  
Л.Е. КОПЕЛЕВИЧ ◽  
А.В. САМОРОДОВ ◽  
Ч. ПЭН
Keyword(s):  
Renewable Energy ◽  
Kinetic Energy ◽  
Total Energy ◽  
Thermal Energy ◽  
Output Voltage ◽  
Renewable Energy Sources ◽  
Electrical Energy ◽  
Energy Sources ◽  
Voltage Regulator ◽  
The Sun

Описаны конструктивные особенности трехвходовой аксиальной генераторной установки (ТАГУ), преобразующей кинетическую энергию ветра и световую энергию солнца и суммирующей механическую, световую и тепловую энергию с одновременным преобразованием полученной суммарной энергии в электрическую. Показаны преимущества ТАГУ перед двухвходовыми генераторными установками. Дополнительное включение стабилизатора напряжения в схему ТАГУ позволило расширить область применения стабилизированной трехвходовой аксиальной генераторной установки за счет стабилизации ее выходного напряжения. The design features of the three-input axial generating installation (TAGI), which converts the kinetic energy of wind and light energy of the sun and sums the mechanical, light and thermal energy with the simultaneous conversion of the total energy into electrical energy, are described. The benefits of TAGI in front of the two-input generating installation shown. The additional introduction of a voltage regulator into the TAGI scheme allowed to expand the scope of the stabilized three-input axial generating installation by stabilizing its output voltage.

scholarly journals Toward fully quantum modelling of ultrafast photodissociation imaging experiments. Treating tunnelling in the ab initio multiple cloning approach

2016 ◽  
Vol 194 ◽  
pp. 81-94 ◽  
Author(s):  
Dmitry V. Makhov ◽  
Todd J. Martinez ◽  
Dmitrii V. Shalashilin
Keyword(s):  
Kinetic Energy ◽  
Ab Initio ◽  
Energy Release ◽  
Kinetic Energy Release ◽  
Total Kinetic Energy ◽  
Recent Effort ◽  
Experimental Measurements ◽  
Quantum Level ◽  
Hydrogen Atoms ◽  
Quantum Simulations

We present an account of our recent effort to improve simulation of the photodissociation of small heteroaromatic molecules using the Ab Initio Multiple Cloning (AIMC) algorithm. The ultimate goal is to create a quantitative and converged technique for fully quantum simulations which treats both electrons and nuclei on a fully quantum level. We calculate and analyse the total kinetic energy release (TKER) spectra and Velocity Map Images (VMI), and compare the results directly with experimental measurements. In this work, we perform new extensive calculations using an improved AIMC algorithm that now takes into account the tunnelling of hydrogen atoms. This can play an extremely important role in photodissociation dynamics.

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.

Sign in / Sign up

Export Citation Format

Share Document