THE EFFECT OF SUBSTITUENTS ON THE DEPROTONATION ENERGY OF SELECTED PRIMARY, SECONDARY AND TERTIARY ALCOHOLS

Ab initio computations were carried out at the Hartree-Fock level of t heory on primary, secondary and tertiary alcohols and also on their de protonated conjugate bases containing methyl and phenyl substituents u sing a variety of basis sets (3-21G, 6-31G and triple-zeta) in combina tion with diffuse and polarization functions. The computed gas phase a cidity as measured by the proton affinity of the conjugate bases (alko xide ions) increased with increasing degree of substitution, in agreem ent with experimental gas phase acidity but in disagreement with exper imental solution acidity trends. The molecular conformations, fundamen tal vibrational frequencies and charge distributions of selected alcoh ols and their conjugate bases were also studied.