H + D? reaction

Vignais PM, Dimon B, Zorin NA, et al. 1997. HupUV proteins of Rhodobacter cap-sulatus can bind H2 evidence from the H-D reaction. J Bacteriol 179 290-2. 

Two limiting cases of this C3(-H) or C3(-D) elimination chemistry are possible. In one mechanism, rapid energy input into the C-H/D reaction coordinate suggests that an excess of energy, beyond the barrier height, can occur. Here one expects a nearly statistical distribution of reaction pathways. Thus, the deuterium number (deuterium exchange fraction) should be 0.5. At more moderate vibrational... 

Next, we focus on the dynamics after ultrafast IR excitation of the main absorption peaks (cf. Fig. 1). The laser pulse spectra are shown in Fig. 2. Clearly, they are broad enough to excite a coherent superposition, i.e., a vibrational wave packet, in both cases. The dynamics is analyzed using the expectation values of the energy of the H/D reaction coordinates, Exy(t) = Ea a( I (t) a) a I (t)), and of the energies of the uncoupled skeleton modes,... 

F.J. Aoiz, L. Banares, V.J. Herrero, V.S. Rabanos, K. Stark, H-J. Werner, The F+HD DF(HF)+H(D) reaction revisited Quasiclassical trajectory study on an ab initio potential energy surface and comparison with molecular beam experiments, J. Chem. Phys. 102 (1995) 9248. 

Figure 4, The experimental cross section for the HD+ + e H+ + D reaction as a function of electron energy, as measured in CRYRING. The vertical dotted line shows the dissociation energy of the HD+ ion. (Reproduced with permission from Ref. [55].)...

Roth, H.D., Reaction of methylene in solutions. Selective abstraction reactions of CHj and CHj, /. Am. Chem. Soc., 93, 4935, 1971 Roth, H.D., Chemically induced nuclear spin polarization in the study of carbene reaction mechanisms, Acc. Chem. Res., 10, 85,1977. 

Rettner C T and Auerbach D J 1996 Quantum-state distributions for the HD product of the direct reaction of H(D)/Cu(111) with D(H) incident from the gas phase J. Chem. Phys. 104 2732... 

Shalashilin D V, Jackson B and Persson M 1999 Eley-Rideal and hot atom reactions of H(D) atoms with D(H)-covered Cu(111) surfaces quasiclassical studies J. Chem. Phys. 110 11 038... 

Sauder D G and Dagdigian P J 1990 Determination of the internal state distribution of NC produced from the H + NG2 reaction J. Chem. Phys. 92 2389-96... 

D Mello M, Duneczky C and Wyatt R E 1988 Recursive generation of individual S-matrix elements application to the collinear H + H2 reaction Chem. Phys. Lett. 148 169... 

Zhang D H and Light J C 1996 Quantum state-to-state reaction probabilities for the H+H2O reaction in six dimensions J. Chem. Phys. 105 1291... 

Example I hc reaction coordinate for rotation about the central carbon-carbon bond in rt-bulane has several stationary points.. A, C, H, and G are m in im a and H, D, an d F arc tn axirn a. Only the structures at the m in im a represen t stable species an d of these, the art/[ con form ation is more stable th an ihc nauchc. 

R. A. Sheldon, Chemicals From Synthesis Gas Catalytic Reactions of CO and H, D. Reidel Publishing Company, 1983, p. 86. 

The Huron-Dow Process. The Huron-Dow (H-D) process is a refinement of the cathodic reduction of oxygen in an alkaline electrolyte yielding low strength hydrogen peroxide directiy. Earlier attempts reHed on neutralizing the excess caustic or forming insoluble metal peroxides (92). The two reactions involved are... 

H. Pines, W. M. StaUck, and H. B. Injovanovich, ed., Base-Cataly d Reactions of Hydrocarbons and Related Compounds, Academic Press, Inc., New York, 1977. 

Solvent for Base-Catalyzed Reactions. The abihty of hydroxide or alkoxide ions to remove protons is enhanced by DMSO instead of water or alcohols (91). The equiUbrium change is also accompanied by a rate increase of 10 or more (92). Thus, reactions in which proton removal is rate-determining are favorably accompHshed in DMSO. These include olefin isomerizations, elimination reactions to produce olefins, racemizations, and H—D exchange reactions. 

Class (2) reactions are performed in the presence of dilute to concentrated aqueous sodium hydroxide, powdered potassium hydroxide, or, at elevated temperatures, soHd potassium carbonate, depending on the acidity of the substrate. Alkylations are possible in the presence of concentrated NaOH and a PT catalyst for substrates with conventional pX values up to - 23. This includes many C—H acidic compounds such as fiuorene, phenylacetylene, simple ketones, phenylacetonittile. Furthermore, alkylations of N—H, O—H, S—H, and P—H bonds, and ambident anions are weU known. Other basic phase-transfer reactions are hydrolyses, saponifications, isomerizations, H/D exchange, Michael-type additions, aldol, Darzens, and similar... 

Tritium was first prepared in the Cavendish Laboratory by Rutherford, OHphant, and Harteck in 1934 (2,3) by the bombardment of deuterophosphoric acid using fast deuterons. The D—D nuclear reaction produced tritium ( D-H D — -H energy), but also produced some He by a... 

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