Reactivity from excited state 4FeO+ + CO sampled through reaction of ground state 4FeCO+ + N2O
Abstract
The kinetics of the FeCO+ + N2O reaction have been studied at thermal energies (300–600 K) using a variable temperature selected ion flow tube apparatus. Rate constants and product branching fractions are reported. The reaction is modestly inefficient, proceeding with a rate constant of 6.2 × 10−11 cm3 s−1 at 300 K, with a small negative temperature dependence, declining to 4.4 × 10−11 cm3 s−1 at 600 K. Both Fe+ and FeO+ products are observed, with a constant branching ratio of approximately 40:60 at all temperatures. Calculation of the stationary points along the reaction coordinate shows that only the ground state quartet surface is initially sampled resulting in N2 elimination; a submerged barrier along this portion of the surface dictates the magnitude and temperature dependence of the total rate constant. The product branching fractions are determined by the behavior of the remaining 4OFeCO+ fragment, and this behavior is compared to that found in the reaction of FeO+ + CO, which initially forms 6OFeCO+. Thermodynamic and kinetic arguments are used to show that the spin-forbidden surface crossing in this region is efficient, proceeding with an average rate constant of greater than 1012 s−1.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jun 15, 2016
- Source ID
- 10.1063/1.4953553
Entities
People
- Albert A Viggiano
- Jordan C. Sawyer
- Nicholas S Shuman
- Oscar Martinez Jr.
- Shaun G Ard
- Steven A. Brown
Organizations
- Air Force Office of Scientific Research
- Air Force Research Laboratory