Physical Chemistry Chemical Physics vol:5 issue:24 pages:5419-5423
A kinetic study of the reaction of ground state Fe atoms (a D-5(4)) with NO2 has been performed in a fast-flow reactor. A microwave-induced plasma afterglow system with H atoms reacting with the gaseous FxCl(3x)(g) oligomers was used as Fe atom source. The Fe atoms were monitored by atomic absorption spectroscopy (AAS) at 248.3 nm. The rate constant k(1) of the reaction Fe + NO2 --> products has been determined at temperatures between 303 and 814 K and was found to be equal to k(1) = (4.8(-0.6)(+0.7)) x 10(-10)exp(-(4.5 +/- 0.4)/RT kJ mol(-1)) cm(3) molecule(-1) s(-1). The mechanistic implications in terms of the "electron-jump" mechanism are also discussed and it was concluded that the concept of "harpooning" is not applicable to reaction (1). Instead, the value of k(1) can remarkably well be simulated in terms of the simple gas kinetic collision model.