Hydrogen exchange between

Covalent. Formed by most of the non-metals and transition metals. This class includes such diverse compounds as methane, CH4 and iron carbonyl hydride, H2Fe(CO)4. In many compounds the hydrogen atoms act as bridges. Where there are more than one hydride sites there is often hydrogen exchange between the sites. Hydrogens may be inside metal clusters. 

Deuterium-labelled Tetralin and deuterium were used to determine incorporation of hydrogen by structural position in the Tetralin and coal products. Approximately two-thirds of the protium incorporated into the Tetralin-di2 was found in the a-alkyl position, indicating that hydrogen exchange between the coal and tetralin involves the a-Tetralinyl radical. In the case of the coal products, the terms 2H >yFy and 1HX (1-Fy) were used to calculate the deuterium and protium contents or eacn structural position. Preferential incorporation was found in the a-aliphatic position of the soluble coal products, indicating that these positions participated preferentially in hydrogen exchange and addition. The... 

Hung, H. C., Hoberman, H. D. Influence of steric specificity on the rates of hydrogen exchange between substrates of NAD-coupled dehydrogenases. Biochem. Biophys. Res. Commun. 46, 399—405 (1972). 

Sepall, O. and Mason, S.G. (1961). Hydrogen exchange between cellulose and water. I. Measurement of accessibility. Canadian Journal of Chemistry, 39, 1934—1943. 

Fig. 16. Reaction coordinate for hydrogen exchange between methane and an acidic zeolite cluster. Arrows represent displacement vectors along the reaction coordinate. Reprinted with permission from Ref. 248. Copyright 1994 American Chemical Society.

Effects of Crystal Size of MoS2 on the Isomerization of 2-Methyl-1-butene and the Hydrogen Exchange between C2HA and C2DA... 

Fig. 19. Geometrical isomers of propene-d, formed in the hydrogen exchange between C3H6 and C3D6 on MoS2 at room temperature (<5). 1976 American Chemical Society.

Fig. 20. Intermolecular hydrogen exchange between (z)-propene-l-d, and propene-d6 in the presence of HD on MoS2 at room temperature (36).

Fig. 21. Hydrogen exchange between l-butene-d0 and l-butene-d8 and their isomerization on cut single crystal catalyst of MoS2 at 100°C, where mw indicates sampling for microwave spectroscopic analysis (14,37).

So far the intermediates of the hydrogenation of olefins have been estimated by a hydrogen exchanged between D2 and olefins during the hydrogenation reaction, where the steps of the alkyl formation in Scheme 14 are assumed to be reversible and to be the main route of the hydrogen-exchange reaction. A historical reaction of olefins with D2 on nickel catalyst... 

Mori, Y., Wakayama, N. Hydrogen Exchange between Deuterium and Charge-Transfer Complexes. J. Catalysis 8, 288 (1967). 

Hogenkamp, H. P. C., Ghambeer, R. K., Brownson, C., Blakley, R. L., and Vitols, E., 1968, Cobamides and ribonucleotide reduction. VI. Enzyme-catalyzed hydrogen exchange between water and deoxyadenosylcobalamin. J. Biol. Chem. 243 7999808. 

Hydrogen exchange between phosphines and deuterated hydroxylic solvents occurs slowly, the rate depending on the acidity of the phosphine. In the presence of acid or base catalysts, exchange is faster and the reactions can be used for deuteriophosphine synthesis, e.g. ... 

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