Kinetic isotope effects for hydrogen abstraction from a series of cycloalkanes and branched alkanes by hydrogen atoms in the gaseous phase

Preparation of crosslinked microspheres and porous solids from hydrocarbon solutions: A new variation of precipitation polymerization chemistry

“…These differences can be attributed to the unique grafting reactivity of cyclooctane relative to other hydrocarbons. As noted earlier, the homolytic CH bond dissociation energy of cyclooctane is considerably less than that found in other hydrocarbons (i.e., 389.6 kJ/mol for C 8 H 15 H versus 400.2 kJ/mol for C 6 H 11 H),42 which makes it more susceptible to radical oxidation,35 and heightens its rate of hydrogen atom donation to alkoxyl33 and alkyl34 radicals. Given the importance of hydrogen transfer to graft initiation and propagation, cyclooctane affords higher RH addition yields and simpler grafting products than other hydrocarbons 43.…”

Physicochemical Properties of Deuterated Compounds. 7th Communication. The H/D exchange between hydrogen and methane over Ni Catalyst

“…The postulated reaction paths go through an excited symmetric vibration mode of methane on a particular site of the surface, so that the tunneling permits a side-by-side adsorption of H and CH,. We had to introduce a similar tunnel effect for the calculation of the isotope effect of the H/D abstraction of alkanes by hydrogen [30]. The similarity of the data of the present work with the data of Winters obtained using a different method is very gratifying and underlines the importance of the isotope effect of the chemisorption for the exchange with H, but not with D [3] [9].…”

“…amounts (20,30,60, 100, and 200 mg) of the catalyst with a diameter of 0.15 mm. The reactors are assembled in series in a temperature-controlled oven (B) to i0.05" by means of a controller (C).…”

Physicochemical Properties of Deuterated Compounds. 8th Communication. The kinetic isotope effect for the reaction of hydrogen atoms with methylcyclohexane and perdeuteromethylcyclohexane in the gas phase

“…This profile is also drawn in Fig. 4, and has been used as a reasonable tunnel path in our previous works [22] [23]. For Case 2, the zero-point energies (ZPEs) are taken into consideration in the calculation of V , and V,, uiz.,…”

“…Theoretical Calculation of the KIE k>/k",. A theoretical interpretation of the KIE for the reaction of H-atoms with cyclohexane, k",k",, has been reported in[22] [23]. However, various possible tunnel paths have not been considered.…”