On the Connection of High-Resolution NMR Spectrum Mirror Symmetry With Spin System Properties

A correlation between the symmetry of NMR spectra, including higher-order spectra, and the properties of the spin system has been established. It is shown that for a spectrum to be symmetric about the mid-resonance frequency (ν0), two conditions must be satisfied: the resonant frequencies of the spins must be symmetrically positioned about ν0, and the J coupling matrix must be symmetric about the secondary diagonal. The results were validated by calculating theoretical spectra for 4-, 5-, and 6-spin systems.