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

The removal of nitrogen trifluoride (NF) is of significant importance in atmospheric chemistry, as NF is an important anthropogenic greenhouse gas. However, the radical species OH and O(D) in atmospheric conditions are nonreactive towards NF. It is necessary to explore possible ways to remove NF in atmosphere. Therefore, the participation of water molecules in the reaction of NF 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 + OH reaction as well. The energy barrier of the S2 mechanism was decreased by 8.52 kcal/mol and 10.58 kcal/mol with the assistance of HO and (HO), respectively. Moreover, the presence of (HO) not only reduced the energy barrier of the reaction, but also changed the product channels, i.e., formation of NFO + (HO)-HF instead of NFOH + (HO)-F. Therefore, the removal of NF 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.