How to observe the elusive resonances in hydrogen atom or deuterium atom + molecular hydrogen .fwdarw. molecular hydrogen or hydrogen deuteride + hydrogen atom reactive scattering

1991 ◽  
Vol 95 (1) ◽  
pp. 12-19 ◽  
Author(s):  
William H. Miller ◽  
John Z. H. Zhang
Keyword(s):  
Hydrogen Atom ◽  
Molecular Hydrogen ◽  
Deuterium Atom ◽  
Reactive Scattering ◽  
Hydrogen Deuteride

scholarly journals Atmospheric deuterium fractionation: HCHO and HCDO yields in the CH<sub>2</sub>DO+O<sub>2</sub> reaction

2007 ◽  
Vol 7 (4) ◽  
pp. 10019-10041 ◽  
Author(s):  
E. Nilsson ◽  
M. S. Johnson ◽  
F. Taketani ◽  
Y. Matsumi ◽  
M. D. Hurley ◽  
...  
Keyword(s):  
Hydrogen Atom ◽  
Ftir Spectroscopy ◽  
Molecular Oxygen ◽  
Molecular Hydrogen ◽  
Branching Ratio ◽  
Hydrogen Atom Transfer ◽  
Photochemical Oxidation ◽  
Oxidation Of Methane ◽  
Methoxy Radical ◽  
Deuterium Enrichment

Abstract. The formation of formaldehyde via hydrogen atom transfer from the methoxy radical to molecular oxygen is a key step in the atmospheric photochemical oxidation of methane, and in the propagation of deuterium from methane to molecular hydrogen. We report the results of the first investigation of the branching ratio for HCHO and HCDO formation in the CH2DO+O2 reaction. Labeled methoxy radicals (CH2DO) were generated in a photochemical reactor by photolysis of CH2DONO. HCHO and HCDO concentrations were measured using FTIR spectroscopy. Significant deuterium enrichment was seen in the formaldehyde product, from which we derive a branching ratio of 88.2±1.1% for HCDO and 11.8±1.1% for HCHO. The implications of this fractionation on the propagation of deuterium in the atmosphere are discussed.

Intra- and inter-molecular hydrogen-atom abstraction of photoexcited 1,4-dimethylanthraquinone

1993 ◽  
Vol 213 (5-6) ◽  
pp. 581-585 ◽  
Author(s):  
Nakayama Toshihiro ◽  
Honma Chisako ◽  
Miki Sadao ◽  
Kumao Hamanoue
Keyword(s):  
Hydrogen Atom ◽  
Molecular Hydrogen ◽  
Hydrogen Atom Abstraction

scholarly journals Interstellar Dust and the H2 Molecule

1965 ◽  
Vol 7 ◽  
pp. 259-264
Author(s):  
K. H. Schmidt
Keyword(s):  
Hydrogen Atom ◽  
Molecular Hydrogen ◽  
Interstellar Dust ◽  
Unit Volume ◽  
Formation Rate ◽  
Dust Particles ◽  
Interstellar Gas ◽  
The Past ◽  
Grain Surface ◽  
H2 Molecule

Nearly 20 Years Ago van de Hulst stated that the formation of molecular hydrogen occurs on the surfaces of the interstellar grains. (See ref. 1.) In the last years several authors discussed the problem of the interstellar abundance of the H2 molecule. (See refs. 2 to 9.) They all found that the percentage of the molecular hydrogen in the interstellar gas probably is much larger than had been thought in the past and that the essential mechanism of H2 formation is the formation on the particle surfaces. Therefore, the formation rate of interstellar H2 is a function of the area of the grain surface per unit volume, which is dependent on the average radius of the grains ā, on the number of dust particles per unit volume N(ā), and on the distribution function of the particle radii. The formation rate is determined by the density of the atomic hydrogen nH and the temperature of the interstellar gas Tgas. Finally, the formation rate of H2 depends on the probability π that an impinging hydrogen atom on a grain joins with another hydrogen atom to form a molecule.

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