The strength of the H-bond donation by alcohols is reflected in the carbon-hydrogen bond of the H-C-O-H functional group. The one-bond 13C-1H spin-spin coupling constant of hexafluoroisopropanol (HFIP) correlates with the strength of the H-bond in various HFIP-amine complexes with a slope of approximately -0.2 Hz in 1JCH per approximately 1 kJ mol(-1) increase in the H-bond enthalpy. The decrease in 1JCH is attributed to an increased overlap of the H-bonding sigma orbital with the antibonding sigma orbitals of the vicinal C-H bonds.