RELATIONS BETWEEN ACCEPTOR NUMBERS OF LEWIS-ACIDS AND OH VIBRATIONS

It is found that the increase of the solvent effect on vibration spect ra of OH groups induced by Lewis acids is linear proportional to the G utmann acceptor numbers AN. This gives a simple method of AN determina tion by OH vibration frequencies and of the understanding of these num bers. The ANs are not only useful for a common characterization of sol vent effects, but for complex formations, too. The significance of the AN values, determined by different methods, and of other methods to c haracterize solvents effects by one single number and the influence of Lewis acids are discussed.