Deuterium Isotope Effects on 14,15N Chemical Shifts of Ammonium Ions: A Solid State NMR Study

Deuterium isotope effects on N14,15 chemical shifts are measured in ammonium halides in the solid state using both enriched N15 salts and N14 natural abundance materials. The effects are correlated to N15 chemical shifts and to N···X distances. The deuterium isotope effects on N14,15 chemical shifts in the solid state are discussed in relation to effects observed in solution. No NH couplings are seen due to fast rotation in the solid, which leads to self-decoupling, whereas ND couplings are present