Theoretical Study of Ionization Potential and Electron Affinity of Different Isomers of Pyridone

The adiabatic (vertical) ionization potential (IP) and valence electron affinity (EA) of gaseous pyridone have been determined with HF method and three DFT methods: B3LYP, B3P86 and B3PW91 at 6-311 ++G(d,p) and 6-311 ++G(2d,2p) basis sets. IPs and EAs of pyridone in solutions have been calculated at the B3LYP/6-311++G(d,p) basis set. IPs and EAs of four isomers of pyridone are both positive values. The IPs in solutions are smaller than the results in the gaseous phase and decrease with the increase of dielectric permittivities in solutions. This finding indicates that the cationic states in solutions are more stable than those in the gaseous phase. All the EAs are negative in the gaseous phase, indicating that the anionic states are unstable with respect to the electron autodetachment, both adiabatically and vertically.