Protonated NF 3O. A G2MS theoretical study on the structure, stability, and interconversion of the (NF 3O)H + isomers

Abstract

The protonation of NF 3O has been investigated by DFT and high-level of theory ab initio calculations. The geometries of the (NF 3O)H + isomers and their interconnecting transition structures have been optimized at the B3LYP/6-31G(d) level of theory and their relative stability and thermochemistry have been evaluated using the G2MS computational procedure. The fluorine-protonated isomer 1a must be viewed as an ion-dipole complex between NF 2O + and HF. It is more stable than the oxygen-protonated isomer 2a by 32.4 kcal mol −1. The proton affinity of NF 3O and the enthalpy of formation of 1a are calculated as 172.0 and 154.7 kcal mol −1, respectively. Both 1a and 2a are stable with respect to their dissociation products and their interconnecting transition structure 3 lies 77.6 kcal mol −1 above that of 1a. Therefore, both 1a and 2a should in principle be observable as distinguishable isomers in the gas phase. The present G2MS theoretical results have been compared with those concerning the strictly related (NF 3)H + isomers.