Relative Acidities of Water and Methanol and the Stabilities of the Dimer Anions

Article abstract of DOI:10.1021/j100283a019

The difference between ΔH⁰_acid of H2O and CH3OH was directly measured to be 9.6 +/- 0.2 kcal/mol at 600 K by variable-temperature pulsed high pressure mass spectrometry.This result defines ΔH⁰_acid(CH3OH) at 300 K as 381.6 +/- 0.7 kcal/mol and also confirms published values of EA(CH3O) and ΔH⁰_D(CH3O-H), H2O was also used as a reference to measure ΔH⁰_acid(C6H6) as 400.7 +/- 0.8 kcal/mol at 600 K.The dissociation energies of the hydrogen-bonded dimers OH^-*H2O (26.8 kcal/mol), CH3O^-*H2O (23.9 kcal/mol), and CH3O^-*CH3OH (28.8 kcal/mol) were also measured.The former two are found to be in very good agreement with pu blished ab initio results.