The intramolecular hydrogen bond in ortho-hydroxy acetophenonesq

The crystal structures of two ortho-hydroxy ketones (5-chloro-2-hydroxyacetophenone (I K) and 3,5-dichloro-2-hydroxyacetophenone (II K)) have been determined with X-ray diffraction at 100 K. A comparison of steric effects on properties of pseudoaromatic hydrogen bonds in ortho-hydroxy acetophenone and ortho-hydroxy ketimines have been carried out with the application of crystallographic data. Nuclear quadrupole resonance (NQR) spectra have been measured and interpreted. q 2004 Elsevier B.V. All rights reserved