Theoretical Investigation of the Relationship between Proton NMR Chemical Shift and Hydrogen Bond Strength.
Hartree-Fock, Møller-Plesset, and DFT (BLYP, B3LYP) calculations have been carried out using the 6-31+G(d,p) basis set to study the relationship between calculated (1)H NMR chemical shifts and calculated hydrogen bond strengths in several model low-barrier hydrogen bond complexes. For both the formic acid-substituted formate anion and enol-substituted enolate anion model systems, we find an excellent linear correlation between calculated hydrogen bond strength and predicted (1)H NMR chemical shift, with an average slope of 1.5 kcal/mol per ppm chemical shift.
Kumar
Ganesh A.
GA
Department of Chemistry, University of North Texas, Denton, Texas 76203.
McAllister
Michael A.
MA