102307-70-0Relevant academic research and scientific papers
Kinetic Isotope Effects for Hydrogen Abstraction from a Series of Cycloalkanes and Branched Alkanes by Hydrogen Atoms in the Gaseous Phase
Fujisaki, Noboru,Ruf, Amanz,Gaeumann, Tino
, p. 1605 - 1610 (2007/10/02)
Hydrogen atoms produced in the radiolysis of water vapor were used to determine the kinetic isotope effects for the reactions H(.) + RH(RD) -> H2(RD) + R(.) H(KD)>, where RH is a perprotiated alkane and RD is the corresponding perdeuterated alkane.The alkanes studied include a homologous series of cycloalkanes, cyclopentane through cyclododecane, and isobutane, 2,3-dimethylbutane, 2,3,4-trimethylpentane, and neopentane.The results were expressed in terms of the Arrhenius-type equation kH/kD = AH/AD expD-EH)(kJ mol-1)/RT>, over the temperature range of 363-463 K.The values for the ratio AH/AD range from 0.32 to 0.75, and the activation energy differences ED-EH vary from 6.8 to 11.0 kJ/mol, depending on the molecular structures of the reactants.The variation in the values of ED-EH was correlated with the bond dissociation energies of the C-H bond being broken.Theoretical calculations based on transition-state theory combined with the London-Eyring-Polanyi-Sato potetial energy surfaces could reproduce the major features of the experimental results when tunnel effects were taken into consideration.
