Medium isotope effect for isobutyrophenone in aqueous solution. Solvent isotope effects on carbonyl group hydration

A medium solvent isotope effect of Φ = 0.827 ± 0.013 was determined for transfer of isobutyrophenone from H 2 O to D 2 O. This result, in conjunction with the average solvent isotope effect on hydration of a number of carbonyl compounds, leads to as the fractionation factor for the hydroxyl group hydrogens of the hydration reactions' gem-diol products, which is consistent with the expectation that fractionation factors for uncharged hydroxyl groups should be unity. Keywords: isobutyrophenone, fractionation factors, solvent isotope effects, deuterium oxide.