Relationships between ¹H, ¹³C and ¹⁷O NMR chemical shifts and H/D isotope effects on ¹³C and ¹⁷O nuclear shielding in intramolecular hydrogen‐bonded systems

Abstract

Abstract The intramolecular Hbond strength in cis ‐enolic forms of β‐diketones was investigated. The correlations between the 1 H hydroxyl proton shieldings and the chemical shifts of the 13 C and 17 O nuclei involved in the chelate ring, and the H/D isotope shifts on the latter resonances, were determined. An increase in the hydrogen bond strength leads to increasing values of H/D isotopic shifts on the 17 O resonances. The results obtained are compared with quantum chemical calculations and x‐ray measurements.