Tautomeric, spectroscopic, DFT calculations and X-ray studies on O2N-4-C6H4-NHN=Q(COCH3)2

This paper deals with the structural and tautomeric studies on O2N-4-phenyl hydrazone derivative of acetylacetone, of formula O2N-4-C6H4NHN=C(COCH3)(2), I, using IR, H-1 NMR and C-13 NMR spectroscopies, X-ray diffraction analysis and quantum mechanical calculations. The crystal lographic data show that this compound has a beta-diketohydrazone structure, containing an intramolecular H-bond assisted by resonance (RAHB), with (NO)-O-... distance of 2.6025(16) angstrom. These results are in agreement with the spectroscopic studies and with theoretical calculations. The collected information confirms that I shows the same structure in CDCl3 solution, solid state and gaseous phase. (c) 2006 Elsevier Ltd. All rights reserved.