Coherence transfer through homonuclear dipolar coupling in an unoriented two spin-1/2 solid-state system

Abstract

Dipolar coupling is a valuable NMR parameter to study the structure and dynamics of solids and partially aligned biological molecules in solution. The transfer of magnetization via the homonuclear dipolar coupling, known as dipolar coherence transfer (DCT), has been used to obtain the internuclear distances between two specific sites of interest in a biological solid. In this study, DCT for a pair of dipolar coupled spin-1/2 nuclei in a powder sample under static experimental condition is analyzed in detail by the numerical calculation of the analytical solutions for the time development of the density matrix. The density matrix evolution under the effect of the homonuclear dipolar interaction is evaluated using the product operator formalism. The effect of scalar coupling on DCT is also discussed.