ESR Study of the Kinetics of the Reactions of D Atoms and O Atoms with NH3

A wide temperature-range study using ESR atom detection has beem employed to measure the rates of the reactions of D atoms and O atoms with NH3. In the case of the deuterium reaction, evidence is presented which shows that the interaction with NH3 proceeds via an exchange process of the type: D+NH3→NH3D+H. This reaction was studied over the temperature range of 423–741°K. The specific rate constant for this exchange reaction was found to be 1.9 ± 0.2 × 1013exp(− 10 100 ± 150 / RT) in units of cubic centimeters mole−1·second−1. The reaction of O atoms with NH3 was studied over the temperature interval of 361–677°K. The specific rate constant obtained for the reaction O+NH3→OH+NH2 was found to be 4.0 ± 0.9 × 1012exp(− 6600 ± 130 / RT) in units of cubic centimeters mole−1·second−1. This Arrhenius pre-exponential factor depends on a stoichiometric factor of 3.50 atoms per NH3 molecule assumed from other work.