The absolute rate constants of the addition of H and D atoms to propylene-d0 and -d6 have been measured by means of the pulse radiolysis-resonance absorption technique over the temperature range of 200–500 K. The rate constants obtained were well expressed by these Arrhenius equations: k(H+C3H6)=(3.00±0.38)exp[−(1612±66)⁄RT], k(H+C3D6)=(2.55±0.57)exp[−(1509±128)⁄RT], k(D+C3H6)=(1.99±0.05)exp[−(1550±15)⁄RT], and k(D+C3D6)=(2.20±0.27)exp[−(1587±67)⁄RT] in units of 10−11 cm3 molecule−1 s−1. The unit of activation energy is cal mol−1. Practically no isotope effects attributable to the difference between C3H6 and C3D6 could be observed. This is similar to the kinetic isotope effects previously observed in the rate constants of the addition of H and D atoms to isotopic ethylenes. The theoretical rate constants of the above reactions have been calculated by the conventional activated complex theory using the potential energy surface drawn by the ab initio method; however, no agreement with regard to the isotope ...
[1]
K. Okazaki,et al.
Temperature Dependence of the Rate Constants of H and D-Atom Additions to C2H4, C2H3D, C2D4, C2H2, and C2D2
,
1981
.
[2]
K. Okazaki,et al.
Kinetic isotope effects in the reaction H + C2H4 → C2H5
,
1981
.
[3]
K. Morokuma,et al.
Ab initio approach to organic reaction rates. Kinetic isotope effects in the reaction H + C/sub 2/H/sub 4/. -->. C/sub 2/H/sub 5/
,
1979
.
[4]
S. Nagase,et al.
Ab initio mechanistic study of radical reactions. Transition states and reaction barriers for the reaction of atomic hydrogen with acetylene
,
1979
.
[5]
W. E. Falconer,et al.
Unimolecular Decomposition of Chemically Activated Propyl Radicals. Normal Intermolecular Secondary Kinetic Isotope Effect
,
1963
.
[6]
R. Cvetanovic,et al.
Relative Rates of Addition of Hydrogen Atoms to Olefines
,
1961
.