Inhomogeneous broadening of two-dimensional NMR lineshapes

Analytical expressions for inhomogeneously broadened two-dimensional NMR lineshapes are derived. It is shown that, if the inhomogeneous broadening is dominant, the homogeneous one-dimensional lineshape can be recovered by taking a simple cross section through the two-dimensional lineshape. Thus, in favourable circumstances, the homogeneous linewidth can be extracted without prior knowledge or removal (via spinning, decoupling or refocusing) of the inhomogeneous broadening. This result is confirmed experimentally.