Hot hydrogen atoms

Kreutz T G and Flynn G W 1990 Analysis of translational, rotational, and vibrational energy transfer in collisions between COj and hot hydrogen atoms the three dimensional breathing ellipse model J. Chem. Phys. 93 452-65... 

The fate of the radicals is thought to be the same as discussed above for the liquid state. In the gas phase the H atoms produced in reactions 22 and 23 are expected to abstract hydrogen from the methyl and to some extent from the OH group. Hot hydrogen atoms might play a role. In the liquid phase hydrogen atom abstraction from the OH group is of even smaller likelihood than... 

A more recent addition to the above reaction scheme is the distinction between thermal and hot hydrogen atoms. A yield of thermal hydrogen atoms of —1.3 is obtained by McCrumb and Schuler (11). All these reactions and yields may be summarized as follows ... 

If Reaction 6 or 7 occurs, the hydrogen yield is reduced, and if Reaction 8 occurs, the cyclohexene yield is increased relative to that of bicyclohexyl. Since hot hydrogen atoms are considered to abstract from cyclohexane much more readily than thermal hydrogen atoms, only thermal hydrogen atoms will be involved in Reactions 6 to 8. 

An assumption of the method is that the average internal excitation energies for the pure and diluted recoil systems are approximately the same. One-dimensional recoil trajectory calculations in the energy coordinate for translational cooling of hot hydrogen atoms have focused on this... 

The photochemistry of methanethioP at 254 and 214 nm as well as the reaction of methanethiol with hot hydrogen atoms produced by photolysis... 

Part of the excitation energy may be transformed to the kinetic energy of dissociation products. This is a route by which hot hydrogen atoms of high reactivity are formed. 

Other work is, however, not in agreement with this finding. For X = Br, investigation of the reactions of the hot atoms, reactions (38) and (39), has bem carried out by photolysis of mixtures of DBr, H2, and Br2 in the absence of added moderator. Hot hydrogen atoms with an average translational energy of about 1 eV were produced by the sequence (46) and (47). Yidds of D2 and HD as a function of the composition of the reaction mixture were interpreted using a... 

Addition of a hot hydrogen atom to ethene (62) produces a superhot ethyl radical CiHf which has a lifetime too short for stabilization at normal pressures. Subsequent decomposition occurs and the net result of reactions (62) and (63) is moderation of H. An arbitrary distinction is drawn between CiHf and CiHt, the normal activated radical produced by addition of tbomalized H to C2H4, whose fate is probably stabilization and reaction with H2S to give ethane. 

In examining reactions of the higher alkenes with hydrogen atoms generated by photolysis of HiS, Woolly and Cvetanovid observed the formation of methane in mixtures of HiS with propene, but-l-ene, 2-methylpropene, and buta-1,3-diene. The persistance of methane production to quite high pressures can be explained by the formation of exo tionally unstable alkyl radicals by addition of hot hydrogen atoms to the alkenes. 

Reactions of Photochemically Generated Hot Hydrogen Atoms H + CH3CH=CHj -> CH3CH2CH CH3CH2CH CHj + C3H4... 

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