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

The self-association of acetanilide through hydrogen bonding between N-H an d O=C in the solvents [H-2(1)]chloroform, [H-2(6)]acetone, [H-2(3)]acetonit rile and [H-2(6)]dimethyl sulphoxide is investigated by high resolution nuc lear magnetic resonance spectroscopy. Dilution shift data for the protons o f the N-H group were measured over a wide range of temperature and concentr ation. The monomer shift, dimer shift and dimerization constant were determ ined by a graphical method operating on the dilution chemical shift data. T he enthalpy and entropy of dimerization were also obtained from the van't H off plot.