Unveiling the Influence of Water Molecules for NF 3 Removal by the Reaction of NF 3 with OH: A DFT Study.

The removal of nitrogen trifluoride (NF ₃ ) is of significant importance in atmospheric chemistry, as NF ₃ is an important anthropogenic greenhouse gas. However, the radical species OH and O( ¹ D) in atmospheric conditions are nonreactive towards NF ₃ . It is necessary to explore possible ways to remove NF ₃ in atmosphere. Therefore, the participation of water molecules in the reaction of NF ₃ with OH was discussed, as water is abundant in the atmosphere and can form very stable complexes due to its ability to act as both a hydrogen bond donor and acceptor. Systemic DFT calculations carried out at the CBS-QB3 and ωB97XD/aug-cc-pVTZ level of theory suggest that water molecules could affect the NF ₃ + OH reaction as well. The energy barrier of the S _N 2 mechanism was decreased by 8.52 kcal/mol and 10.58 kcal/mol with the assistance of H ₂ O and (H ₂ O) ₂ , respectively. Moreover, the presence of (H ₂ O) ₂ not only reduced the energy barrier of the reaction, but also changed the product channels, i.e., formation of NF ₂ O + (H ₂ O) ₂ -HF instead of NF ₂ OH + (H ₂ O) ₂ -F. Therefore, the removal of NF ₃ by reaction with OH is possible in the presence of water molecules. The results presented in this study should provide useful information on the atmospheric chemistry of NF ₃ .