THEORETICAL CALCULATION OF INTRINSIC ACIDITY AND BASICITY OF FOH

Ab initio calculations have been used to study the intrinsic basicity and acidity of hypofluorous acid (FOH), which plays a key role as an i ntermediate in the interaction of Fz with water. At the G2 level of th eory, the proton affinity and deprotonation enthalpy of FOH were predi cted to be 135.3 and 360.3 kcal/mol at 298 K, respectively. In particu lar, the latter value is in excellent agreement with the best availabl e thermodynamically calculated one. The computational results show tha t FOH is a significantly stronger acid (by ca. 24 kcal/ mel) and a wea ker base (by ca. 30 kcal/mol) than H2O. The influence of the replaceme nt of one hydrogen atom in water molecule with F atom on its acid-base properties is rationalized in terms of field-inductive, polarizabilit y, resonance, and adjacent lone pair-lone pair interaction effects.