Synthesis, structure and Hirshfeld surface analysis of 1,3-bis[(1-octyl-1H-1,2,3-triazol-4-yl)methyl]-1H-benzo[d]imidazol-2(3H)-one

The title molecule adopts a conformation resembling a two-bladed fan with the octyl chains in fully extended conformations. In the crystal, the molecules are linked by C—H⋯O and C—H⋯N hydrogen bonds and C—H⋯π interactions.


Chemical context
Benzimidazolone derivatives display diverse pharmacological and biological properties including antiviral (Ferro et al., 2017), antibacterial (Saber et al., 2020;Mentes ¸e et al., 2021), anticancer (Guillon et al., 2022), anti-Alzheimer's (Mo et al., 2020), antifungal (Ibrahim et al., 2021), and antioxidant (Ibrahim et al., 2021) activities.In our ongoing research in this area, we are synthesizing compounds that combine the 1,2,3triazole motif with benzimidazol-2-one derivatives.In this report, we present the synthesis and structure of the title compound, C 29 H 44 N 8 O, which was obtained using click chemistry, specifically the copper-catalysed azide-alkyne cycloaddition (CuAAC) method.Additionally, we describe the Hirshfeld surface analysis and calculations on crystal voids and intermolecular interaction energies and energy frameworks.

Hirshfeld surface analysis and computational chemistry
In order to further visualize the intermolecular interactions in the crystal of the title compound, a Hirshfeld surface (HS) analysis was carried out by using Crystal Explorer 17.5 (Turner et al., 2017) The title molecule with 50% probability ellipsoids.

Figure 2
A portion of one chain of molecules viewed along the a-axis direction with C-H� � �O hydrogen bonds depicted by dashed lines and noninteracting hydrogen atoms omitted for clarity.at d e = d i = 1.12A ˚.The pair of characteristic wings in the fingerprint plot delineated into H� � �N/N� � �H contacts (15.7% contribution to the HS; Fig. 5c) is viewed as pair of spikes with the tips at d e + d i = 2.30 A ˚.In the presence of C-H� � �� interactions, the H� � �C/C� � �H contacts, contributing 10.4% to the overall crystal packing, are reflected in Fig. 5d with the tips at d e + d i = 2.69 A ˚.The pair of characteristic wings in the fingerprint plot delineated into H� � �O/O� � �H contacts (4.8% contribution to the HS; Fig. 5e) is viewed as pair of spikes with the tips at d e + d i = 2.32 A ˚. Finally, the C� � �N/N� � �C (Fig. 5f) and N� � �N (Fig. 5g) contacts, with 0.4% and 0.2% contributions, respectively, to the HS, have very low distributions of points.
A void analysis was performed by summing the electron densities of the spherically symmetric atoms contained in the asymmetric unit (Turner et al., 2011).The void surface is defined as an isosurface of the procrystal electron density and is calculated for the whole unit cell where the void surface meets the boundary of the unit cell and capping faces are generated to create an enclosed volume.The volume of the crystal voids (supplementary Fig. S1) and the percentage of free space in the unit cell are calculated to be 198.6 and 13.4A ˚3, respectively.
The intermolecular interaction energies were calculated using the CE-B3LYP/6-31G(d,p) energy model available in Crystal Explorer 17.5 (Turner et al., 2017).The total intermolecular energy (E tot ) is the sum of electrostatic (E ele ), polarization (E pol ), dispersion (E dis ) and exchange-repulsion (E rep ) energies (Turner et al., 2015) with scale factors of 1.057, 0.740, 0.871 and 0.618, respectively (Mackenzie et al., 2017).Energy frameworks were constructed for E ele (red cylinders), E dis (green cylinders) and E tot (blue cylinders) (supplementary Fig. 2a and 2b).These data indicate that dispersion energy is the most important contributor to the cohesion of the crystal structure of the title compound.The theoretical optimization of the title structure in the gas phase was conducted by density functional theory (DFT), using the standard B3LYP functional and 6-311 G(d,p) basis-set calculations (Becke, 1993).The energy band gap [�E = E LUMO -E HOMO ] of the molecule is 5.04 eV, and the frontier molecular orbitals, E HOMO and E LUMO have relative energies of À 5.72 and 0.68 eV, respectively (supplementary Tables 1 and 2 and supplementary Fig. S3).

Special details
Experimental.The diffraction data were obtained from 7 sets of frames, each of width 0.5° in ω or φ, collected with scan parameters determined by the "strategy" routine in APEX3.The scan time was 25 sec/frame.Geometry.All esds (except the esd in the dihedral angle between two l.s.planes) are estimated using the full covariance matrix.The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry.An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s.planes.Refinement.Refinement of F 2 against ALL reflections.The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 .The threshold expression of F 2 > 2sigma(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement.R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.H-atoms attached to carbon were placed in calculated positions (C-H = 0.95 -0.99 Å).All were included as riding contributions with isotropic displacement parameters 1.2 -1.5 times those of the attached atoms.Refined as a 2component inversion twin.108.9 H29A-C29-H29B 109.5 C14-C15-H15A 108.9 C28-C29-H29C 109.5 C16-C15-H15B 108.9 H29A-C29-H29C 109.5 C14-C15-H15B 108.9 H29B-C29-H29C 109.5 H15A-C15-H15B 107.7

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å
Figure 1

Figure 3
Figure 3 Packing viewed along the b-axis direction with C-H� � �O and C-H� � �N hydrogen bonds depicted, respectively, by black and light-blue dashed lines.The C-H� � ��(ring) interactions are depicted by dark-green dashed lines and non-interacting hydrogen atoms omitted for clarity.

Figure 4
Figure 4View of the three-dimensional Hirshfeld surface of the title compound plotted over d norm in the range À 0.24 to 1.57 a.u.

Figure 5
Figure 5 The full two-dimensional fingerprint plots for the title compound, showing (a) all interactions, and delineated into (b) H� � �H, (c) H� � �N/ N� � �H, (d) H� � �C/C� � �H, (e) H� � �O/O� � �H, (f) C� � �N/N� � �C and (g) N� � �N interactions.The d i and d e values are the closest internal and external distances (in A ˚) from given points on the Hirshfeld surface.

Table 2
Experimental details.