Fast reactions of displacement of hydrogen atoms from valence-saturated compounds by atomic deuterium

The specific kinetic features of a class of fast gas-phase reactions of the direct displacement of atoms from valence-saturated polyatomic molecules i nteracting with an atomic reactant discovered by the author are considered. An EPR-based technique for studying the kinetics of reactions of free atom s and radicals is described, which makes it possible to consider the role o f longitudinal diffusion under flow conditions and requires no knowledge of absolute concentrations of the atomic reactant. For a wide temperature ran ge, the experimental rate constants for abstraction and displacement reacti ons between free deuterium atoms and various types of hydrogen-containing c ompounds and reactions of hydrogen atoms with a number of hydrocarbons are reported. The kinetic isotope effect of the heterogeneous recombination of hydrogen and deuterium atoms on quartz is studied. It is suggested that rea ctions of atom displacement from molecules should be considered when studyi ng mechanisms of complex processes with the use of isotopes.