NMR dynamic frequency shifts and the quadrupolar interaction

A brief account of the quadrupolar interaction is presented. It is demonstrated that second-order dynamic frequency shifts must be considered for multipolar nuclides relaxed by spacially isotropic quadrupolar interactions. Hence, each single quantum coherence is characterized by a unique precessional frequency. A short discussion of the intensities and evolution of these transverse magnetization composites is also included for completeness. The findings of this work supplement the theory of spin 3/2 quadrupolar labelling and exchange techniques as applied to biomolecular systems.