Manchester NMR Methodology Group

Lineshape calculations are reported for a spin system consisting of a spin-1/2 nucleus scalar-coupled to two magnetically equivalent spin-1 nuclei, e.g., a CD2 group. It is found that, because of the differential line broadening, the peak height ratio of the five spin-1/2 nucleus transitions is expected to deviate from the integrated intensity ratio of 1:2:3:2:1, The deviation is dependent on the extent of cross-correlation between the two quadrupolar interactions. The theoretical predictions for peak height ratios and for bandshapes are tested for the carbon-13 spectrum of perdeuterated ethylene glycol, and iterative fitting is used to obtain an estimate of the extent of the correlation between the quadrupolar interactions for the two deuterons, (C) 1999 Academic Press.