Multiple quantum NMR and relaxation of an oriented CH3 group

NMR relaxation of the n-quantum transitions (n=1,2,3) for an oriented CH3 group by paramagnetic impurities is discussed. The n-quantum spectra are presented, and the effect of the correlation of fluctuations in random fields at the three proton sites on symmetry-breaking relaxation transitions is outlined. Experimental results on acetonitrile dissolved in liquid crystalline EBBA with paramagnetic DTBN are presented together with a discussion on correlations of fluctuation and correlation times.