The problem of internal motion of molecules in the liquid as seen from NMR relaxation studies

Abstract

As a brief introduction the most important formulas are given and the crucial physical aspects will be worked out. It is essentially the Woessner theory which gives the framework of the facts to be treated. A number of experimental results are presented for the following molecules: Methanol, acetic acid, DMSO, ethanol, i-propanol, toluene and propylene carbonate. It will be shown that the proton-proton distances in the molecule which result from the proton relaxation data obtained in the dispersion range together with the “classical” theory do not agree with the generally accepted molecular geometry. Moreover, the general nature of the resulting motion in its qualitative and basic features does not correspond to the pattern generally accepted. A very general description of the molecule is given which is free of the difficulties which have appeared.