A 1H NMR study of crystal nucleation in solution

Solution NMR data can provide information about the interactions of molecules in the first stages of crystallisation, and H-1 NMR complexation-induced changes in chemical shift can be used to determine high resolution three-dimensional structures of complexes in solution. The concentration-dependent changes in H-1 NMR chemical shift of two different compounds have been used to make predictions about how these compounds pack in the crystalline state. The structures of dimer motifs characterised in solution agree very well with the structures of dimers found in the corresponding X-ray crystal structures. Solution NMR experiments therefore provide an experimental tool for probing the organisation of molecules in the solid state.