Nuclear magnetic relaxation due to slow molecular reorientation and fast internal rotation interference

Abstract

The relaxation of the two-proton system longitudinal magnetization Mz(t) is considered theoretically, using the Bloch equations with a diffusion term. The condition τc ≥ 1, τ ≪ 1 is fulfilled here, where is the energy of the proton dipole-dipole interaction, τ is the correlation time of molecular diffusion rotation and τ is the correlation time for the proton rotation relative to the molecule. Unlike the ordinary Bloch equations a two-exponential law for the evolution of Mz(t) is obtained for definite values , τc and τ. The results of the present work may be useful for the consideration of the system having mobile proton groups in viscous media.