Abstract

This work deals about the synthesis and characterization of compounds containing the pyrazole core belonging to the family of (E)-4-((3,5-dimethyl-1-(4-R-phenyl)-1H-pyrazol-4-yl)diazenyl)benzonitrile, with possible application as ligands in inorganic chemistry. These compounds were obtained by reaction of a substituted arylhydrazine, R-C6H4-NHNH2, R: 4-OCH3, 4-CH3, 4-F, 4-H, 4-Cl, 4-CF3, 4-CN, 3-Cl, 3-NO2, 2-Cl and perfluorophenylhydrazine, C6F5-NH2NH; with a beta-diketohydrazone precursor of formula (CH3CO)(2)C=N-NH-C6H4-4-CN. Analytical techniques (MP and EA) and spectroscopic methods such as UV-Vis, IR, H-1 NMR, C-13 NMR were employed to characterize the prepared systems. One of the synthesized compounds yielded in ethanol single crystals suitable for X-ray diffraction study. In order to model all the studied compounds and the molecular orbitals involved in the transitions, DFT and TDDFT calculations were performed. The non-variability of the bond distances suggests the robustness of the conjugated structure formed by the R-C6H4-pyrazole-N=N-benzonitrile rings, which is poorly affected by the change of the substituents over the phenyl ring. (C) 2014 Elsevier Ltd. All rights reserved.