Crystal structure and Hirshfeld surface analysis of two 5,11-methano-benzo[g][1,2,4]triazolo[1,5-c][1,3,5]oxa-diazo-cine derivatives.

In the title compounds, 9-bromo-2,5-dimethyl-11,12-di-hydro-5H-5,11-methano-benzo[g][1,2,4]triazolo[1,5-c][1,3,5]oxa-diazo-cine, C13H13BrN4O (I), and 7-meth-oxy-5-methyl-2-(pyridin-4-yl)-11,12-di-hydro-5H-5,11-methano-benzo[g][1,2,4]tri-azolo[1,5-c][1,3,5]oxa-diazo-cine, C18H17N5O2 (II), the triazole ring is inclined to the benzene ring by 85.15 (9) and 76.98 (5)° in compounds I and II, respectively. In II, the pyridine ring is almost coplanar with the triazole ring, having a dihedral angle of 4.19 (8)°. In the crystal of I, pairs of N-H⋯N hydrogen bonds link the mol-ecules to form inversion dimers with an R 2 2(8) ring motif. The dimers are linked by C-H⋯π and C-Br⋯π inter-actions forming layers parallel to the bc plane. In the crystal of II, mol-ecules are linked by N-H⋯N and C-H⋯O hydrogen bonds forming chains propagating along the b-axis direction. The inter-molecular inter-actions were investigated using Hirshfeld surface analysis and two-dimensional fingerprint plots, and the mol-ecular electrostatic potential surface was also analysed. The Hirshfeld surface analysis of I suggests that the most significant contributions to the crystal packing are H⋯H (42.4%) and O⋯H/H⋯O (17.9%) contacts. For compound II, the H⋯H (48.5%), C⋯H/H⋯C (19.6%) and N⋯H/H⋯N (16.9%) inter-actions are the most important contributions.