Intramolecular hydrogen bonds in some 1,3-bis(arylimino)isoindolines

The intramolecular hydrogen bonding in three derivatives of 1,3-bis(arylimino)isoindolinones (Fig. 1) have been investigated by multinuclear NMR techniques in both solution and in the solid state. In all cases, the symmetric three center (bifurcated) hydrogen bonds have been detected. The 3-aminopyridine derivative, which cannot form intramolecular hydrogen bond has been used as a model compound for non-bonded structure. The results obtained from NMR measurements have been compared with IR and X-ray experiments. The full conformity of all results was achieved. q 2004 Elsevier B.V. All rights reserved.