Why is sulfuric acid a much stronger acid than ethanol? Determination of the contributions by inductive/field effects and electron-delocalization effects.

Two different and complementary computational methods were used to determine the contributions by inductive/field effects and by electron-delocalization effects toward the enhancement of the gas-phase deprotonation enthalpy of sulfuric acid over ethanol. Our alkylogue extrapolation method employed density functional theory calculations to determine the deprotonation enthalpy of the alkylogues of sulfuric acid, HOSO2-(CH2CH2)n-OH, and of ethanol, CH3CH2-(CH2CH2)n-OH. The inductive/field effect imparted by the HOSO2 group for a given alkylogue of sulfuric acid was taken to be the difference in deprotonation enthalpy between corresponding (i.