Similarities and differences in the crystal packing of halogen‐substituted indole derivatives. Issue 4 (24th July 2018)

• Record Type: Journal Article
• Authors: Shukla, Rahul; Singh, Paramveer; Panini, Piyush; Chopra, Deepak
• Is Part Of: Acta crystallographica. Volume 74:Issue 4(2018:Aug.)
• Page Start: 376
• Page End: 384
• Publication Date: 2018-07-24
• Subjects: hydrogen bonds -- isostructurality -- indole derivatives -- structural diversity -- halogenated carbazoles -- intermolecular interactions -- crystal structure -- quantum theory of atoms in molecules (QTAIM) -- lattice energy
• DOI: 10.1107/S2052520618008090
• Languages: English
• ISSNs: 2052-5206

Abstract

Abstract : The crystal structures of newly synthesized halogenated indoles bring out the essential similarity and differences in intermolecular interactions in the solid state. The roles of N—H…π and C—H…π interactions establish the key role of such interactions in modulating the crystal packing; their significance is established from both energetics from the PIXEL method and topological analysis of the electron density from quantum theory of atoms in molecules (QTAIM). Abstract : The role of different intermolecular interactions in the crystal structures of halogen‐substituted indoles which are fused with six‐membered or seven‐membered cyclic rings is investigated here. Several crystal structures show isostructural characteristics due to the presence of similar supramolecular motifs. In the absence of any strong hydrogen bonds, the molecular packing of reported structures is primarily stabilized by the presence of non‐classical N—H…π and C—H…π interactions in addition to C—H… X ( X = F/Cl/Br) interactions. The nature and energetics of primary and secondary dimeric motifs are partitioned into the electrostatics, polarization, dispersion and exchange–repulsion components using the PIXEL method. Short and directional N—H…π interactions are further explored by a topological analysis of the electron density based on quantum theory of atoms in molecules.