Ab initio molecular dynamics study of the superacid system SbF5/HF solution

We have investigated one of the strongest superacid systems, SbF5 in liquid HF, by ab initio molecular dynamics simulation. In dilute solution a barri erless, diffusion-limited fluorination reaction takes place to form the SbF 6- anion and H2F+ cation. The initial contact ion pair evolves to become a fully separated ion pair by a series of stepwise, incoherent proton jumps. On average, the SbF6- anion had an octahedral structure with the average bo nd length of 1.9 Angstrom. The cationic species is a protonated HF chain, w hich mediates the fast proton jump process.