The Multiple Quantum Coherence and Magic Anglein Solid NMR Spectroscopy

Abstract

In this paper, we discussed that how multiple quantum coherence develops in the anisotropic distribution of dipolar couplings. The magnitude of dipolar couplings varied with oriented angles. The larger dipolar coupling was, the bigger frequency of multiple quantum coherence was. The multiple quantum coherence is decided with proportion of the magnitude of dipolar couplings. The theory equation for the multiple quantum coherence and magic angle 54.7°in solid NMR spectroscopy was verified in this study. The excitation pattern of n-quantum coherence, which can induce the effective size to characterize spin system, is expected in a larger and more complicated spin system for understanding of the relation of dipolar coupling and multiple quantum coherence.