The interaction of anhydrous formic acid with model amides has been studied using infrared, nmr, viscosity, conductance, and density measurements. Several equilibria are needed to describe this interaction over the entire mixing range of acid and amide: hydrogen bonding is prevalent over the entire mixing range, protonation of the amides occurs at high acid concentrations, and ion pair formation is present at intermediate acid concentrations. The data are consistent with protonation and hydrogen bonds involving the acidic proton of formic acid and the amide carbonyl oxygen. The degree of protonation, as measured directly by the specific conductance, reflects the basicities of the different amide carbonyls.
ASJC Scopus subject areas
- Colloid and Surface Chemistry