Akademik Məlumat İdarəetmə Sistemi
ChemistrySelect, vol.10, no.46, 2025 (SCI-Expanded, Scopus)
This article discusses the synthesis of aromatic azo compounds based on tert-butylbenzaldehyde. The synthesized compounds (E)-1-(1-(4-(tert-butyl)phenyl)-2,2-dichlorovinyl)-2-(4-chlorophenyl)diazene (I), (E)-1-(2,2-dibromo-1-(4-(tert-butyl)phenyl)vinyl)-2-phenyldiazene (II), and (E)-1-(2,2-dibromo-1-(4-(tert-butyl)phenyl)vinyl)-2-(4-methoxyphenyl)diazene (III) were characterized by 1H and 13C NMR spectroscopy. Moreover, the crystal structure of compounds was explored by single-crystal X-ray diffraction (SC-XRD) analysis. The diffraction analysis showed that the substitution on the aromatic ring affects the dihedral angle between rings, and a distinction between supramolecular assemblies is noticed. The inclination between aromatic rings is 79.96 (4)°, 78.76 (8)°, and 77.42 (7)° for compounds I–III, respectively. The supramolecular assembly of compounds I and II is stabilized by C–H⋅⋅⋅Cl and C–H⋅⋅⋅O bonding, respectively, whereas compound III has no conventional H-bonding. The H⋯π interactions are observed at distances of 2.85 Å in compound I and 2.88 Å in compounds II and III, whereas the corresponding halogen⋯π distances are 3.6260 (7), 3.5660 (13), and 3.7934 (10) Å for compounds I, II, and III, respectively. The H⋯H contact predominates in the supramolecular assembly (34.4%, 44.2%, and 42.6% for I–III), along with notable H⋯halogen and H⋯carbon interactions in all compounds. Furthermore, the crystal structure data have been employed to theoretically determine UV–visible, FT-IR, NMR, highest occupied molecular orbital (HOMO)–lowest unoccupied molecular orbital (LUMO) energies, frontier molecular orbitals, and molecular electrostatic potential through the DFT/B3LYP/6-311+g(2d,p) level of theory. The HOMO–LUMO energy gaps are 5.75, 5.26, and 5.23 eV for compounds I–III, respectively, indicating that the bromo-substituted derivative is the most reactive among them. The DFT results were found to be consistent with the experimental findings.