The vibrational dependence of bond lengths in nuclear spin dipole relaxation

Abstract

It is shown that the dipole-dipole relaxation behaviour in liquid state nuclear magnetic resonance spectroscopy is determined by products of two of the expectation values taken over the vibrational wavefunctions of the inverse cubes of the internuclear distances. The derivation of this result, which shows that the relaxation behaviour is not determined by the expectation value of the inverse sixth power of the internuclear distances, assumes that the periods of vibration of the normal modes of each molecule are much smaller than any rotational correlation times.