Kinetic parameters for direct atomic substitution reactions

Experimental data (the rate constants and activation energies) for seven reactions of direct substitution of one atom for another D + CH3R --> CH2DR + H, D + NH3 --> DNH2 + H, D + H2O --> HOD + H, F + CH3X --> CH3F + X (X = F, Cl, Br, and 1) involving atoms D and F and molecules C2H6, H2O, NH3, CH3F, CH3Cl, CH3Br, and CH3I are analyzed using the parabolic model of a bimolecular radical reaction. The activation energies for the thermally neutral analogs of these substitution reactions are calculated. Atomic substitution involving deuterium atoms has a lower activation energy of a thermally neutral reaction than radical abstraction or substitution.