View in EDS

The role of π–π, C–H⋯halogen, and halogen⋯π interactions in the crystal packing of 9-aminoacridinium 3-halobenzoate salts: an experimental and theoretical investigation.

Saved in:
Bibliographic Details
Title: The role of π–π, C–H⋯halogen, and halogen⋯π interactions in the crystal packing of 9-aminoacridinium 3-halobenzoate salts: an experimental and theoretical investigation.
Authors: Nowak, Patryk1 (AUTHOR), Sikorski, Artur1 (AUTHOR), Mirocki, Artur1 (AUTHOR) artur.mirocki@ug.edu.pl
Source: Structural Chemistry. Jun2026, Vol. 37 Issue 3, p1191-1202. 12p.
Subjects: Intermolecular interactions, Stacking interactions, Molecular self-assembly, Computational chemistry
Abstract: The crystal structures of 9-aminoacridinium 3-halobenzoate salts (X = Cl, Br, I) were compared in terms of molecular packing and intermolecular interactions. All three compounds crystallize in the monoclinic P2₁/c space group, are isomorphous, and exhibit a high degree of structural similarity with closely related packing motifs. Analysis of geometric parameters confirms proton transfer from the carboxylic group of the acid to the endocyclic nitrogen atom of 9-aminoacridine, consistent with ΔpKa predictions indicating salt formation. Analysis of intermolecular interactions shows that the crystal packing is stabilized by a network of N–H⋯O and C–H⋯O hydrogen bonds, as well as π–π stacking, C–H⋯halogen, and halogen⋯π interactions. Geometric analysis of the halogen⋯π contacts indicates that these interactions can be classified as weak n–π* interactions. Energy framework calculations demonstrate that the energetic stability of the crystals increases with halogen size (I > Br > Cl), in agreement with the observed melting points, and highlight the dominant role of dispersion forces in stabilizing the supramolecular architecture across all three structures. [ABSTRACT FROM AUTHOR]
Copyright of Structural Chemistry is the property of Springer Nature and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: Engineering Source
Description
Abstract:The crystal structures of 9-aminoacridinium 3-halobenzoate salts (X = Cl, Br, I) were compared in terms of molecular packing and intermolecular interactions. All three compounds crystallize in the monoclinic P2₁/c space group, are isomorphous, and exhibit a high degree of structural similarity with closely related packing motifs. Analysis of geometric parameters confirms proton transfer from the carboxylic group of the acid to the endocyclic nitrogen atom of 9-aminoacridine, consistent with ΔpKa predictions indicating salt formation. Analysis of intermolecular interactions shows that the crystal packing is stabilized by a network of N–H⋯O and C–H⋯O hydrogen bonds, as well as π–π stacking, C–H⋯halogen, and halogen⋯π interactions. Geometric analysis of the halogen⋯π contacts indicates that these interactions can be classified as weak n–π* interactions. Energy framework calculations demonstrate that the energetic stability of the crystals increases with halogen size (I > Br > Cl), in agreement with the observed melting points, and highlight the dominant role of dispersion forces in stabilizing the supramolecular architecture across all three structures. [ABSTRACT FROM AUTHOR]
ISSN:10400400
DOI:10.1007/s11224-026-02758-w