CENTRO DE QUIMICA INORGANICA "DR. PEDRO J. AYMONINO"
Unidad Ejecutora - UE
On the roles of close shell interactions in the structure of acyl-substituted hydrazones: An experimental and theoretical approach
M. IFZAN ARSHAD; SAEED, AAMER; BOLTE, MICHAEL; DELGADO ESPINOSA, ZULY YULIANA; FANTONI, ADOLFO; ERBEN, MAURICIO FEDERICO
SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY.
PERGAMON-ELSEVIER SCIENCE LTD
Lugar: Amsterdam; Año: 2016 vol. 157 p. 138 - 138
The 2-(phenyl-hydrazono)-succinic acid dimethyl ester compound was synthesized by reacting phenylhydrazinewith dimethylacetylene dicarboxylate at room temperature and characterized by elemental analysis, infrared,Raman, 1H and 13C NMR spectroscopies and mass spectrometry. Its solid state structure was determined by X-raydiffraction methods. The X-ray structure determination corroborates that the molecule is present in the crystal asthe hydrazone tautomer, probably favored by a strong intramolecular N?H···O_C hydrogen bond occurringbetween the carbonyl (?C_O) and the hydrazone ?C_N?NH? groups. A substantial fragment of the molecularskeleton is planar due to an extended π-bonding delocalization. The topological analysis of the electron densities(Atom in Molecule, AIM) allows characterization of intramolecular N?H···O interaction, that can be classified asa resonant assisted hydrogen bond (RAHB). Moreover, the Natural Bond Orbital population analysis confirms thata strong hyperconjugative lpO1 → σ*(N2?H) remote interaction between the C2_O1 and N2?H groups takesplace. Periodic system electron density and topological analysis have been applied to characterize the intermolecularinteractions in the crystal. Weak intermolecular interactions determine the crystal packing, and the prevalence ofnon-directional dispersive contributions are inferred on topological grounds. The IR spectrum of the crystallinecompound was investigated by means of density functional theory calculations carried out with periodic boundaryconditions on the crystal, showing excellent agreement between theory and the experiments. The vibrationalassignment is complemented with the analysis of the Raman spectrum.