Utilizing Hirshfeld surface calculations, non-covalent interaction (NCI) plots and the calculation of interaction energies in the analysis of molecular packing

Abstract

The analysis of atom-to-atom and/or residue-to-residue contacts remains a favoured mode of analysing the molecular packing in crystals. In this contribution, additional tools are highlighted as methods for analysis in order to complement the `crystallographer's tool', PLATON [Spek (2009). Acta Cryst. D65, 148–155]. Thus, a brief outline of the procedures and what can be learned by using Crystal Explorer [Spackman & Jayatilaka (2009). CrystEngComm 11, 19–23] is presented. Attention is then directed towards evaluating the nature, i.e. attractive/weakly attractive/repulsive, of specific contacts employing NCIPLOT [Johnson et al. (2010). J. Am. Chem. Soc. 132, 6498–6506]. This is complemented by a discussion of the calculation of energy frameworks utilizing the latest version of Crystal Explorer. All the mentioned programs are free of charge and straightforward to use. More importantly, they complement each other to give a more complete picture of how molecules assemble in molecular crystals.

Luminogens for Aggregation‐Induced Emission via Titanium‐Mediated Double Nucleophilic Addition to 2,5‐Dialkynylpyridines: Formation and Transformation of the Emitting Aggregates

“…[45] In order to visualize the intermolecular interactions in the crystal,n ormalized contact distances (d norm )w ere mapped onto the molecular Hirschfeld surface( Figure 2). [48][49][50][51] As expected, the local minimao fd norm are often associated with fluorine substituents involved in weak intermolecular H···F bonds ( Figure 2). The lack of fluorine substituents in 2 and therefore the absence of intermolecular H···F contacts is expected to result in al ess pronounced RIM.…”

Ion‐Pairing Assemblies of Porphyrin–AuIII Complexes in Combination with π‐Electronic Receptor–Anion Complexes

“…Hirshfeld surface analysis of 1 a + mapped over shape‐index and curvedness properties indicates that the packing structures of 1 a + ‐ 2 a – d ⋅Cl − are also stabilized by π–π interaction (Figure , Supporting Figures 16–19) . In particular, the surfaces of 1 a + ‐ 2 a ⋅Cl − show the red and blue triangles arranged in bow‐tie shapes on the shape‐index surface and a flat region on the curvedness surface, indicating the characteristic mapping pattern for π–π stacking of receptor–anion complexes and the core part of 1 a + …”

Different packing motifs in the crystal structures of three molecular salts containing the 2-amino-5-carboxyanilinium cation: C7H9N2O2 +·Cl−, C7H9N2O2 +·Br− and C7H9N2O2 +·NO3 −·H2O

“…Table 3 Hydrogen-bond geometry (Å , ) for (III). Symmetry codes: (i) x À 1; y; z À 1; (ii) Àx þ 1; y À 1 described by Tan et al (2019). The Hirshfeld surfaces of the cations in (I), (II) and (III) (see supplementary materials) show the expected red spots of varying intensity corresponding to close contacts resulting from the hydrogen bonds described above.…”