Influence of substituent position on molecular structure of Br/MeO-benzylideneanilines in crystal
Full article
| Journal |
Journal of Molecular Structure
ISSN: 0022-2860
, E-ISSN: 1872-8014
|
| Output data |
Year: 2026,
Volume: 1353,
Article number
: 144639,
Pages count
:
DOI:
10.1016/j.molstruc.2025.144639
|
| Authors |
Kartashian Manuk A.
1,2
,
Samigullina Aida I.
1
,
Erokhin Kirill S.
1
|
| Affiliations |
| 1 |
N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Science, Leninsky Prosp., 47, Moscow, 119991, Russian Federation
|
| 2 |
Mendeleev University of Chemical Technology of Russia, Miusskaya Square 9, Moscow, 125047, Russia
|
|
Funding (1)
|
1
|
N. D. Zelinsky Institute of Organic Chemistry Russian Academy of Sciences
|
|
In this study, we present the synthesis and structural analysis of new derivatives from a series of Br-/MeO-substituted N-benzylideneanilines. These products were obtained using an efficient green grinding method that does not require solvent or acid catalysis. X-ray diffraction analysis revealed the structures of the new bromo/methoxy‑benzylideneaniline derivatives, which differ in the number and position of methoxy groups, and the position of the bromine atom in the aryl ring. Quantum chemical calculations were performed to simulate IR spectra and to compare with experimental data. It was demonstrated that 2,3,5-trimethoxy-p-Br-benzylideneaniline crystallizes in two distinct forms. Single-crystal X-ray diffraction revealed that these compounds, despite their conjugated systems and similar geometries, adopt non-planar geometries in the solid state, with the dihedral angle between aromatic rings varying significantly (5.33° to 57.02°). DFT optimization showed that, in the absence of crystal packing effects, the molecules adopt a twisted geometry with dihedral angle ∼40° for all compounds. A comparative analysis with related structures from the CSD underscores the uniqueness of the observed conformational distortions. In the crystal structures, C–H···O interactions play a key role, with their contribution increasing as the number of methoxy groups rises. Examining di- and tri-MeO-substituted N-benzylideneanilines, it was demonstrated that the position of the bromine atom affects these interactions. In p-Br-substituted derivatives, hydrogen atoms from the MeO fragments are involved, whereas in m- and o-Br-substituted derivatives, the hydrogen atom from the phenyl ring adjacent to the Br participates.