The NMR Measurement of the Hydrogen Bonding of Proton Donors Having More Than one Equivalent Proton

Abstract In the hydrogen bonding of a protonic acid having more than one equivalent proton to a n-donor, the K, δH and δS parameters can be measured by NMR spectrometry without any ambiguity as in the case of a single-proton acid, but the measured hydrogen-bond chemical shift is reduced in magnitude as it is the weighted average of the chemical shift of the bonded proton and that of the proton(s) remaining free in the dimer-complex.