Study of association of alcohols in aprotic solvents by multinuclear NMR

Binary mixtures of alcohols（ethyl,n-butyl and n-amyl）with several aprotic sol-vents,such as acetone,dioxane,THF,DMSO and DMF have been studied systematically by1H,13C,15N and 17O NMR measurements.The concentration dependence of chemical shift ofthe solvent was used to evaluate equilibrium constants of the complexation of alcohols withthe solvents.A relationship between the proton shift of alcohol uncombined with the solventand its concentration was found,and the fraction of unassociated hydroxyl groups was thusquantitatively described.The effect of solvent on self association and complexation of thealcohol is discussed on the basis of the electron donicity of the solvents.