Strong hydrogen bonding in the polyfluorides: ab initio calculations and a new method of preparing potassium hydrogendifluoride

Abstract

Ab initio LCAO-MO-SCF calculations have been performed on the polyfluoride ions H_nF_n+1 ^–, n= 1–4, and the hydrogen fluoride polymers (HF)_m, m= 1–4, to determine their molecular configurations and the hydrogen-bond energies of the polyfluorides. All the polyfluorides are strongly hydrogen bonded and have structures in which a central fluorine acts as the acceptor to one to four HF molecules. The hydrogen fluoride polymers prefer open-chain arrangements. A safe and simple method of preparing K[HF₂] in high yield is given.