Transition State for the Hydrogen–Iodine and the Hydrogen Exchange Reactions

1968 ◽  
Vol 49 (8) ◽  
pp. 3739-3740 ◽  
Author(s):  
Roald Hoffmann
Keyword(s):  
Transition State ◽  
Hydrogen Exchange ◽  
Exchange Reactions

Franck–Condon simulations of transition-state spectra for the OH + H2O and OD + D2O reactions

2020 ◽  
Vol 22 (36) ◽  
pp. 20685-20692
Author(s):  
Yutaro Sugiura ◽  
Toshiyuki Takayanagi
Keyword(s):  
Wave Packet ◽  
Transition State ◽  
Hydrogen Exchange ◽  
Exchange Reactions ◽  
Reduced Dimensions ◽  
Quantum Wave ◽  
Franck Condon ◽  
Measured Transition

Quantum wave packet calculations in reduced dimensions were performed to analyze the experimentally measured transition-state spectra of the OH + H2O and OD + D2O hydrogen exchange reactions.

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.

The mechanism of the pinacol-pinacone rearrangement. V. Carbon isotope effects

1957 ◽  
Vol 10 (1) ◽  
pp. 7 ◽  
Author(s):  
JF Duncan ◽  
KR Lynn
Keyword(s):  
High Temperature ◽  
Transition State ◽  
Carbon Isotope ◽  
Isotope Effects ◽  
Alternative Mechanism ◽  
Alternative Route ◽  
Temperature Reaction ◽  
Exchange Reactions ◽  
Carbonium Ion ◽  
High Temperature Reaction

The intermolecular isotope effects of methyl-labelled and alcoholic carbon-labelled pinacol converted to pinacone have been studied over a temperature range of 60-113.5 �C. Tests were made to establish the validity of the results by using two starting materials for synthesizing methyl-labelled pinacol, and several different methods of analysing the products. The isotope effects were determined by measurements made both on (i) pinacol and (ii) pinacone. The results above 80 �C can be interpreted in terms of the synartetic ion mechanism provided both the carbonium ion and the transition state are largely unhydrated, and both the formation of the carbonium ion and the methyl migration are slow steps. Below 60 �C an alternative mechanism is operative. Unless unsuspected exchange reactions are present, the results suggest that the transition state is not so greatly distorted from a simple ethane-type configuration as in the high temperature reaction. Results at intermediate temperatures indicate that the alternative route proceeds via a stable intermediate.

Tritium as a tracer in coal liquefaction. 4. Hydrogen-exchange reactions between hydrogen in coals and tritiated hydrogen molecule

1991 ◽  
Vol 5 (3) ◽  
pp. 459-463 ◽  
Author(s):  
Toshiaki Kabe ◽  
Toshiyuki Horimatsu ◽  
Atsushi Ishihara ◽  
Hideo Kameyama ◽  
Kyoko Yamamoto
Keyword(s):  
Hydrogen Molecule ◽  
Hydrogen Exchange ◽  
Coal Liquefaction ◽  
Exchange Reactions
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