Site of protonation in aniline and substituted anilines in the gas phase: a study via the local hard and soft acids and bases concept

Analysis of the gas-phase protonation site in aniline and substituted anilines using the hard and soft acids and bases (HSAB) system show that DFT-based reactivity can simulate the experimentally observed preferable protonation sites. However, the descriptors for relative nucleophilicity and local polarizability exhibit greater reliability than the local softness descriptor.