Structural properties and electron transfer reactivity of NX3/NX3+ (X=H, F) coupling systems

The geometries and vibrational frequencies of NH3, NH3+, NF3, NF3+ as well as their encounter complexes ((NH3⋯NH3)+ and (NF3⋯NF3)+) are calculated using DFT and ab initio methods at 6-311++G** basis set level. This paper also discusses the inapplicability of DFT methods in predicting the dissociation energy curves, especially for the systems at large contact distance, due to the 'inverse symmetry breaking' problem. Finally, the contact distance dependence of the activation energy, the coupling matrix element and the electron-transfer rate has been analyzed at MP2/6-311++G** level. For the NX3/NX3+ (X=H, F) coupling systems, electron transfer occurs chiefly over a range of contact distance, 2.00 Å