A nuclear magnetic resonance study of hydrogen bonding of δ-valerolactam

The association of amide groups of δ-valerolactam through hydrogen bonding has been investigated by means of high resolution nuclear magnetic resonance spectroscopy in CCl4 and CDCl3 solutions. Chemical shifts of the NH proton signal were measured over a wide range of temperatures and concentrations. Thermodynamic properties associated with the [Formula: see text] hydrogen bond formation were evaluated from a least squares analysis by a direct search procedure with a digital computer. The obtained enthalpy values for hydrogen bond formation are in general agreement with results obtained by other methods.