Michele Krempp

The gas-phase acidity of hindered amines and some reaction chemistry of their corresponding amide ions

Abstract The gas-phase acidities of three hindered amines have been determined by equilibrium measurements using tandem flowing afterglow-selected-ion flow tube technology. These amines, tert-butylamine (ΔH°acid = 396.6 kcal mol−1), di-sec-butylamine (ΔH°acid = 386.1 kcal mol−1), and 2,2,6,6-tetramethylpiperidine (ΔH°acid = 387.5 kcal mol−1), were chosen because of their hindered nature and differing substitution patterns. The ion/molecule chemistry of the anions corresponding to these amides was studied in detail. This demonstrated quite different reactivity patterns, which are discussed in terms of steric properties and other structural features. Thus, primary and secondary substituted amides can be differentiated by reactions with N2O and ND3, and di-sec-butylamide has a strong tendency to act as a hydride donor.