Crystal structures of 2,3,8,9,14,15-hexamethyl-5,6,11,12,17,18-hexaazatrinaphthylene and 2,3,8,9,14,15-hexaphenyl-5,6,11,12,17,18-hexazatrinaphthylene dichloromethane disolvate

2,3,8,9,14,15-Hexamethyl- and 2,3,8,9,14,15-hexaphenyl-5,6,11,12,17,18-hexazatrinaphthylene (HATNMe6 and HATNPh6) are derivatives of hexaazatrinaphthylene (HATN). In the crystal structures of the two compounds, pronounced π–π stacking dominates the packing.

The crystal structures of two substituted HATN (hexaazatrinaphthylene) derivatives, namely 2, 3,8,9,14,3,8,9,14,6,11,12,17, and HATNPh 6 ), are reported. Whereas the structure of the methyl-substituted derivative (HATNMe 6 ) contains no solvent molecules (C 30 H 24 N 6 ), the hexaphenylsubstituted structure (HATNPh 6 ) contains two molecules of dichloromethane (C 60 H 36 N 6 Á2CH 2 Cl 2 ). This class of planar bridging ligands is known for its electron-deficient systems and its ability to formstacking interactions. Indeed, in both crystal structures strongstacking interactions are observed, but with different packing features. The dichloromethane molecules in the crystal structure of HATNPh 6 are situated in the voids and are involved in C-HÁ Á ÁN contacts to the nitrogen atoms of the pyrazine units.

Supramolecular features
As a result of thestacking ability of trinaphthylene derivatives HATNMe 6 (1) and HATNPh 6 (2), these molecules stack in layers in their respective crystal structures. In the crystal packing of HATNMe 6 (1), a herringbone-like arrangement of molecules is observed (Figs. 3 and 4). Individual molecules are arranged in layers and have a short planeto-plane distance (defined by the central rings) of 3.3602 (5) Å . However, theoverlap occurs only in small areas, as shown by the rather large parallel displacement of the molecules with an angle of 31.52 and a shift of 5.48 Å between the centroids. The resulting layers within the The structures of the molecular entities in 2. Displacement ellipsoids are drawn at the 50% probability level. H atoms are drawn as spheres of arbitrary size.

Figure 1
The molecular structure of 1 with the atom labelling and displacement ellipsoids drawn at the 50% probability level. H atoms are given as spheres of arbitrary size. Unlabelled atoms are generated by the symmetry operation (1 À x, y, 1 2 À z).
herringbone-like structure stack at an angle of 63.1 to each other. The molecules of HATNPh 6 (2) form centrosymmetric dimers that are stacked perfectly parallel by van der Waals interactions but with a parallel displaced -stacking. The plane-to-plane distance (defined by the central rings) within a dimer of 3.2518 (5) Å is shorter compared to the corresponding distance in 1. This distance, as well as the short centroid-to-centroid distance of 3.4018 (7) Å are both at the lower limit of ranges known for metal complexes with aromatic nitrogen-containing ligands (Janiak, 2000). The plane-to-plane distance between adjacent dimers is 3.15 Å . The parallel displacement between the layers (Fig. 5) is much shorter than for HATNMe 6 (1), with an angle of 16.8 and a shift of approximately 1 Å . Comparing the plane-to-plane distances of the title compounds with related derivatives like HATN (Alfonso & Stoeckli-Evans, 2001; 3.66 Å ) and HAT(CONH 2 ) 6 (Beeson et al., 1996;3.31 Å ), the dimers of HATNPh 6 (2) have the shortest contact and the shortest displacement in -stacking. Further interactions between the terminal phenyl rings and the pyrazines rings interconnect the dimers. The dichloromethane solvent molecules are located near the electron lone pairs of the N atoms in the voids of the packed molecules. They bridge two molecules of 2 and consolidate the crystal packing through weak C-HÁ Á ÁN hydrogen-bonding interactions (
Synthesis of 1. HATNMe 6 was synthesized by a published procedure (Catalano et al., 1994). Crystals suitable for single crystal X-ray diffraction were obtained by slow evaporation of a benzene solution of 1.
Synthesis of 2. HATNPh 6 was synthesized based on a literature method (Gao et al., 2009). 4,5-diphenyl-1,2-diamine (1.8 g, 6.9 mmol) and hexaketocyclohexane octahydrate (0.54 g, 1.72 mmol) in 100 ml acetic acid were heated up to 373 K for 36 h under a nitrogen atmosphere. After cooling to room temperature the reaction mixture was filtrated and the resulting yellow solid was washed with plenty of water and 2 M KOH solution. The solid was suspended in a mixture of dichloromethane (100 ml) and a saturated K 2 CO 3 solution (100 ml) overnight in order to remove all traces of acetic acid. After filtration and washing with water, the solid was dried in a vacuum to give 2 as a yellow solid in 72% yield. Crystals suitable for single crystal X-ray diffraction were obtained by slow evaporation of a CH 2 Cl 2 solution of 2.

Refinement
Crystal data, data collection and structure refinement details are summarized in Table 2. Hydrogen atoms bound to C atoms were located from difference-Fourier maps but were subsequently fixed to idealized positions using appropriate riding models.

sup-2
Acta Cryst. (2018). E74, 167-171 Special details 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.
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 ) 0.62730 (10) 0.49478 (7) 0.43437 (8)    where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max = 0.001 Δρ max = 0.84 e Å −3 Δρ min = −0.84 e Å −3 Special details 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.