Hydrogen-exchange reactions via hot hydrogen atoms produced in the dissociation process of molecular hydrogen on Ir{111}

2001 ◽  
Vol 115 (21) ◽  
pp. 9947-9959 ◽  
Author(s):  
Kousuke Moritani ◽  
Michio Okada ◽  
Mamiko Nakamura ◽  
Toshio Kasai ◽  
Yoshitada Murata
Keyword(s):  
Molecular Hydrogen ◽  
Hydrogen Exchange ◽  
Exchange Reactions ◽  
Hydrogen Atoms ◽  
Dissociation Process

Estimation of hydrogen mobility in coal using a tritium tracer method. Hydrogen exchange reactions of coals with tritiated water and molecular hydrogen

1993 ◽  
Vol 7 (3) ◽  
pp. 362-366 ◽  
Author(s):  
Atsushi Ishihara ◽  
Hisao Takaoka ◽  
Eri Nakajima ◽  
Yuko Imai ◽  
Toshiaki Kabe
Keyword(s):  
Molecular Hydrogen ◽  
Hydrogen Exchange ◽  
Tritiated Water ◽  
Exchange Reactions ◽  
Tracer Method

Nickel-catalysed hydrogen exchange of aniline, phenol, and their alkylated derivatives with deuterium oxide

1967 ◽  
Vol 20 (2) ◽  
pp. 297 ◽  
Author(s):  
CG Macdonald ◽  
JS Shannon
Keyword(s):  
Aromatic Ring ◽  
Hydrogen Exchange ◽  
Deuterium Oxide ◽  
Electron Donors ◽  
Hydroxyl Groups ◽  
Exchange Reactions ◽  
Hydrogen Atoms ◽  
Catalytic Exchange ◽  
Deuterium Distribution

Selective exchange of hydrogen atoms ortho to amino or hydroxyl groups, together with benzylic hydrogen atoms in aniline, phenol, and their C- alkylated derivatives, was achieved by allowing these compounds to react with deuterium oxide over nickel on kieselguhr at 99�. In addition to the benzylic hydrogen atoms, alkyl hydrogen atoms farther from the aromatic ring underwent slower exchange. Hydrogen atoms ortho to methoxyl did not exchange. Mechanisms of the catalytic exchange reactions are discussed in the light of the results of deuterium distribution measurements and poisoning experiments with electron donors.

Transalkylierung und protonenkatalysierte C-C-Spaltung bei n-Butyl-und n-Pentylbenzol in der Gasphase / Transalkylation and Proton Catalyzed C-C-Cleavage of Gaseous n-Butyl and w-Pentyl Benzenes

1979 ◽  
Vol 34 (3) ◽  
pp. 495-501 ◽  
Author(s):  
C. Wesdemiotis ◽  
H. Schwarz ◽  
C. C. Van de Sande ◽  
F. Van Gaever
Keyword(s):  
Hydrogen Exchange ◽  
Closed Shell ◽  
Open Shell ◽  
Molecular Ions ◽  
Exchange Reactions ◽  
Intramolecular Exchange ◽  
Carbon Carbon Bond ◽  
Exchange Processes ◽  
Reaction Channels ◽  
Alkyl Benzenes

Abstract The investigation of several 13carbon and deuterium labelled n-butyl and n-pentyl benzenes demonstrate that chemical ionization (reagent gas: methane) induces specific carbon-carbon bond cleavages of the alkyl group. The extent of competing reaction channels as for instance direct alkene elimination versus dealkylation/reprotonation is analyzed. Partial hydrogen exchange processes between reagent ions and substrate molecules are restricted to the phenyl ring. Intramolecular exchange reactions between the side chain and the aromatic ring which are typical for the open shell molecular ions of alkyl benzenes are not observed for analogous closed shell cations.

Catalytic deuterium exchange reactions with organics. XXIV. Electron spin resonance studies of adsorption on platinum oxide

1966 ◽  
Vol 19 (4) ◽  
pp. 529 ◽  
Author(s):  
IT Ernst ◽  
JL Garnett ◽  
WA Sollich-Baumgartner
Keyword(s):  
Transition Metal Oxides ◽  
Hydrogen Exchange ◽  
Platinum Oxide ◽  
Active Species ◽  
Paramagnetic Species ◽  
Charge Transfer Complexes ◽  
Severe Reaction ◽  
Exchange Reactions ◽  
Spin Resonance ◽  
Solid Liquid

The formation of paramagnetic species on catalyst surfaces at room temperature through the interaction of polynuclear aromatics in solid, liquid, or solute form with hydrated platinum oxide (PtO2,2H2O) is reported. The results are attributed to the formation of charge-transfer complexes, where the transferred electrons couple weakly, forming essentially a "diradicaloid" complex with a low-lying, thermally populated, triplet state. The effect of solvent, particle size, oxygen, water of crystallization, and temperature on the generation and stability of these e.s.r. active species has been investigated. The possible importance of these paramagnetic species in catalytic self-activation and hydrogen exchange reactions has been discussed. The following Group VIII transition metal oxides gave no e.s.r. spectra under relatively severe reaction conditions such as 1 hr at 120�: PdO; Ru02,2H20; RuO2; Rh2O3; IrO2,2H2O; ReO2; and NiO.

Catalytic deuterium exchange reactions with organics. XIII. Characteristic reactions of the Group VIII transition metals

1965 ◽  
Vol 18 (7) ◽  
pp. 1003 ◽  
Author(s):  
JL Garnett ◽  
WA Sollich
Keyword(s):  
Transition Metal ◽  
Hydrogen Exchange ◽  
Deuterium Oxide ◽  
Metal Catalysts ◽  
Transition Metal Catalysts ◽  
Group Viii ◽  
Exchange Reactions ◽  
Substitution Mechanism ◽  
Π Complex ◽  
Complex Adsorption

Activation procedures and hydrogen exchange reactions with six Group VIII transition metal catalysts (Pt, Pd, Ru, Rh, Ir, Ni) are reported for three characteristic reaction systems: (i) deuterium oxide/benzene, (ii) deuterium oxide/naphthalene, and (iii) deuterium oxide/n-octane. Results of these exchange reactions indicate that both π-complex adsorption and the dissociative π-complex substitution mechanism previously established for platinum are applicable to other Group VIII transition metal catalysts. For general catalytic labelling with isotopic hydrogen, platinum was found to be the most efficient of the catalysts investigated.

Electron Energy Distribution Functions of Hydrogen: The Effect of Superelastic Vibrational Collisions and of the Dissociation Process

1979 ◽  
Vol 34 (5) ◽  
pp. 585-593 ◽  
Author(s):  
M. Capitelli ◽  
M. Dilonardo
Keyword(s):  
Boltzmann Equation ◽  
Energy Distribution ◽  
Electron Energy ◽  
Distribution Functions ◽  
Electron Energy Distribution ◽  
Hydrogen Atoms ◽  
Dissociation Process ◽  
Excitation Rate ◽  
The Boltzmann Equation ◽  
Energy Distribution Functions

Abstract Electron energy distribution functions (EDF) of molecular H2 have been calculated by numerically solving the Boltzmann equation including all the inelastic processes with the addition of superelastic vibrational collisions and of the hydrogen atoms coming from the dissociation process. The population densities of the vibrational levels have been obtained both by assuming a Boltz-mann population at a vibrational temperature different from the translational one and by solving a system of vibrational master equations coupled to the Boltzmann equation. The results, which have been compared with those corresponding to a vibrationally cold molecular gas, show that the inclusion of superelastic collisions and of the parent atoms affects the EDF tails without strongly modifying the EDF bulk. As a consequence the quantities affected by the EDF bulk, such as average and characteristic energies, drift velocity, 0-1 vibrational excitation rate are not too much affected by the inclusion of superelastic vibrational collisions and of parent atoms, while a strong influence is observed on the dissociation and ionization rate coefficients which depend on the EDF tail. Calculated dissociation rates, obtained by EDF's which take into account both the presence of vibrationally excited molecules and hydrogen atoms, are in satisfactory agreement with experimental results.

Sign in / Sign up

Export Citation Format

Share Document