Crystal structure and Hirshfeld surface analysis of 4-azido-2-(3,5-di-methyl-phen-yl)-5-(4-nitro-phen-yl)-2H-1,2,3-triazole.

In the title compound, C16H13N7O2, the 3,5-di-methyl-phenyl and 4-nitro-phenyl rings are inclined to the central 2H-1,2,3-triazole ring by 1.80 (7) and 1.79 (7)°, respectively, and to one another by 2.16 (7)°. In the crystal, the mol-ecules are linked by C-H⋯N hydrogen bonds and π-π stacking inter-actions [centroid-to-centroid distances = 3.7295 (9) and 3.7971 (9) Å], forming ribbons along the b-axis direction. These ribbons are connected to each other by weak van der Waals inter-actions and the stability of the crystal structure is ensured. A Hirshfeld surface analysis of the crystal structure indicates that the most important contributions to the crystal packing are from H⋯H (31.5%), N⋯H/H⋯N (19.2%), O⋯H/H⋯O (14.5%), N⋯C/C⋯C (10.9%) and C⋯H/H⋯C (10.2%) contacts.

Crystal structures and Hirshfeld surface analyses of (E)-1-[1-(4-tert-butyl-phen-yl)-2,2-di-chloro-ethen-yl]-2-phenyl-diazene, (E)-1-[1-(4-tert-butyl-phen-yl)-2,2-di-chloro-ethen-yl]-2-(4-methyl-phen-yl)diazene, (E)-1-[1-(4-tert-butyl-phen-yl)-2,2-di-chloro-ethen-yl]-2-(4-meth-oxy-phen-yl)diazene and (E)-1-[1-(4-tert-butyl-phen-yl)-2,2-di-chloro-ethen-yl]-2-(3-methyl-phen-yl)diazene.

The crystal structures and Hirshfeld surface analyses of four similar azo compounds are reported. (E)-1-[1-(4-tert-Butyl-phen-yl)-2,2-di-chloro-ethen-yl]-2-phenyl-diazene, C18H18Cl2N2, (I), and (E)-1-[1-(4-tert-butyl-phen-yl)-2,2-di-chloro-ethen-yl]-2-(4-methyl-phen-yl)diazene, C19H20Cl2N2, (II), crystallize in the monoclinic space group C2/c with Z = 8, and (E)-1-[1-(4-tert-butyl-phen-yl)-2,2-di-chloro-ethen-yl]-2-(4-meth-oxy-phen-yl)diazene, C19H20Cl2N2O, (III), in the monoclinic space group P21/c with Z = 4. (E)-1-[1-(4-tert-Butyl-phen-yl)-2,2-di-chloro-ethen-yl]-2-(3-methyl-phen-yl)diazene, C19H20Cl2N2, (IV), crystallizes in the triclinic space group P with Z = 4 and comprises two mol-ecules (A and B) in the asymmetric unit. In the crystal structures of (I) and (II), mol-ecules are linked by C-H⋯π and C-Cl⋯π inter-actions, forming layers parallel to (02), while mol-ecules of (III) are linked by C-H⋯O contacts, C-H⋯π and C-Cl⋯π inter-actions forming layers parallel to (02). The stability of the mol-ecular packing is ensured by van der Waals forces between these layers. In the crystal structure of (IV), mol-ecules are linked by C-H⋯π and C-Cl⋯π inter-actions, forming a tri-periodic network.

Crystal structure and Hirshfeld surface analysis of (E)-2-(4-bromo-phen-yl)-1-[2,2-di-bromo-1-(4-nitro-phen-yl)ethen-yl]diazene.

The mol-ecule of the title compound, C14H8Br3N3O2, consists of three almost planar groups: the central di-bromo-ethenyldiazene fragment and two attached aromatic rings. The mean planes of these rings form dihedral angles with the plane of the central fragment of 26.35 (15) and 72.57 (14)° for bromine- and nitro-substituted rings, respectively. In the crystal, C-H⋯Br inter-actions connect mol-ecules, generating zigzag C(8) chains along the [100] direction. These chains are linked by C-Br⋯π inter-actions into layers parallel to (001). van der Waals inter-actions between the layers aid in the cohesion of the crystal packing. The most substantial contributions to crystal packing, according to a Hirshfeld surface analysis, are from Br⋯H/H⋯Br (20.9%), C⋯H/H⋯C (15.2%), O⋯H/H⋯O (12.6%) and H⋯H (11.7%) contacts.

Crystal structures and Hirshfeld surface analyses of the two isotypic compounds (E)-1-(4-bromo-phen-yl)-2-[2,2-di-chloro-1-(4-nitro-phen-yl)ethen-yl]diazene and (E)-1-(4-chloro-phen-yl)-2-[2,2-di-chloro-1-(4-nitro-phen-yl)ethen-yl]diazene.

In the two isotypic title compounds, C14H8BrCl2N3O2, (I), and C14H8Cl3N3O2, (II), the substitution of one of the phenyl rings is different [Br for (I) and Cl for (II)]. Aromatic rings form dihedral angles of 60.9 (2) and 64.1 (2)°, respectively. Mol-ecules are linked through weak X⋯Cl contacts [X = Br for (I) and Cl for (II)], C-H⋯Cl and C-Cl⋯π inter-actions into sheets parallel to the ab plane. Additional van der Waals inter-actions consolidate the three-dimensional packing. Hirshfeld surface analysis of the crystal structures indicates that the most important contributions for the crystal packing for (I) are from C⋯H/H⋯C (16.1%), O⋯H/H⋯O (13.1%), Cl⋯H/H⋯Cl (12.7%), H⋯H (11.4%), Br⋯H/H⋯Br (8.9%), N⋯H/H⋯N (6.9%) and Cl⋯C/C⋯Cl (6.6%) inter-actions, and for (II), from Cl⋯H / H⋯Cl (21.9%), C⋯H/H⋯C (15.3%), O⋯H/H⋯O (13.4%), H⋯H (11.5%), Cl⋯C/C⋯Cl (8.3%), N⋯H/H⋯N (7.0%) and Cl⋯Cl (5.9%) inter-actions. The crystal of (I) studied was refined as an inversion twin, the ratio of components being 0.9917 (12):0.0083 (12).