5-(4-Hexyl-1H-1,2,3-triazol-1-yl)-2,1,3-benzoxadiazole

The title compound, C₁₄H₁₇N₅O, a 1,2,3-triazole derivative of benzoxadiazole (C₁₄H₁₇N₅O), was synthesized via Cu-catal­ysed azide–alkyne cyclo­addition (CuAAC) from the corres­ponding n-octyne and 4-azido­benzoxadiazole. The benz­oxa­diazole and triazole rings show a roughly planar orientation [dihedral angle between the ring planes = 12.18 (5)°]. The alkane chain adopts a zigzag conformation, which deviates from the central triazole ring by 20.89 (6)°. These two torsion angles result in an overall twist to the structure, with a dihedral angle of 32.86 (7)° between the benzoxadiazole group and the hexyl chain. The crystal structure features C—H...N hydrogen bonds leading to chains propagating along [2-10] and offset parallel stacking inter­actions of the triazole and benzoxadiazole rings. The centroid of the extended π-system formed by the benzoxadiazole and triazole rings (14 atoms total) was calculated; the centroid–centroid distance was 4.179 Å, interplanar separation was 3.243 Å, and the resulting offset was 2.636 Å.

5-(1-Benzyl-1H-1,2,3-triazol-4-yl)-2,1,3-benzoxadiazole

In the title compound, C₁₅H₁₁N₅O, which was prepared as part of a study to identify fluoro­genic substrates for the Cu-catalysed azide–alkyne cyclo­addition (CuAAC) reaction, the benzoxa­diazole unit and the triazole ring are much more closely coplanar [dihedral angle = 10.92 (7)°] than either is to the benzyl group [dihedral angles = 69.13 (3)° and 78.20 (4)°, respectively]. The crystal structure features two different sets of weak inter­molecular C—H...N inter­actions between adjacent benzoxadiazole and triazole rings, forming a chain that propagates in the [-110] direction parallel to the ab plane.

1-[1-(2,1,3-Benzoxadiazol-5-ylmeth­yl)-1H-1,2,3-triazol-4-yl]hexan-1-one

The title compound, C₁₅H₁₇N₅O₂, was synthesized as part of a series of benzoxadiazole analogs which were examined for fluorescent properties by Cu-catalysed azide–alkyne cyclo­addition (CuAAC) of a 4-azido­methyl-benzoxadiazole substrate. The structure shows a nearly coplanar orientation of the hexa­none keto group and the 1,2,3-triazole ring [dihedral angle = 4.3 (3)°], while the benzoxadiazole and triazole groups are much more severely inclined [dihedral angle = 70.87 (4)°]. In the crystal, weak C—H...N inter­actions connect translationally-related triazole rings, while another set of C—H...N inter­actions is formed between inversion-related benzoxadiazole units, forming a three-dimensional network. The crystal studied was a non-merohedral twin with refined value of the twin fraction of 0.2289 (16).