The formation of hydrogen bonds produces higher displacement values. The presence of acidic hydrogens can be detected by adding deuterated water, which produces the exchange of acidic hydrogen for deuterium, with the consequent disappearance of the signal. \begin{equation} CH_3OH + D_2O \rightleftharpoons CH_3OD + HDO \end{equation} The most common acid hydrogen shifts in organic molecules are:

  • Carboxylic acids (RCOOH) $\delta$ = 10 - 12 ppm
  • Amines ($R-NH_2$) $\delta$ = 0.5 - 5 ppm
  • Amides ($RCONH_2$) $\delta$ = 5-8 ppm
  • Alcohols (ROH) $\delta$ = 0.5 - 5 ppm
  • Phenols (Ph-OH) $\delta$ = 4 - 7 ppm