NMR study of self-association of acetanilide in chloroform, acetone, acetonitrile and dimethyl sulphoxide

Abstract

The self-association of acetanilide through hydrogen bonding between N-H and O=C in the solvents [H-2(1)]chloroform, [H-2(6)]acetone, [H-2(3)]acetonitrile and [H-2(6)]dimethyl sulphoxide is investigated by high resolution nuclear magnetic resonance spectroscopy. Dilution shift data for the protons of the N-H group were measured over a wide range of temperature and concentration. The monomer shift, dimer shift and dimerization constant were determined by a graphical method operating on the dilution chemical shift data. The enthalpy and entropy of dimerization were also obtained from the van't Hoff plot.