Crystal structure and Hirshfeld surface analysis of two 5,11-methanobenzo[g][1,2,4]triazolo[1,5 c][1,3,5]oxadiazocine derivatives

Abstract

In the title compounds, 9-bromo-2,5-dimethyl-11,12-dihydro-5H-5,11-methanobenzo[g][1,2,4]triazolo[1,5-c][1,3,5]oxadiazocine,C13H13BrN4O(I),and 7-methoxy-5-methyl-2-(pyridin-4-yl)-11,12-dihydro-5H-5,11-methanobenzo[g][1,2,4] triazolo[1,5-c][1,3,5]oxadiazocine, C18H17N5O2 (II), the triazole ring is inclined to the benzene ring by 85.15 (9) and 76.98 (5)degrees 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)degrees. In the crystal of I, pairs of N-H center dot center dot center dot N hydrogen bonds link the molecules to form inversion dimers with an R-2(2)(8) ring motif. The dimers are linked by C-H center dot center dot center dot pi and C-Br center dot center dot center dot pi interactions forming layers parallel to the bc plane. In the crystal of II, molecules are linked by N-H center dot center dot center dot N and C-H center dot center dot center dot O hydrogen bonds forming chains propagating along the b-axis direction. The intermolecular interactions were investigated using Hirshfeld surface analysis and two-dimensional fingerprint plots, and the molecular electrostatic potential surface was also analysed. The Hirshfeld surface analysis of I suggests that the most significant contributions to the crystal packing are H center dot center dot center dot H (42.4%) and O center dot center dot center dot H/H center dot center dot center dot O (17.9%) contacts. For compound II, the H center dot center dot center dot H (48.5%), C center dot center dot center dot H/H center dot center dot center dot C (19.6%) and N center dot center dot center dot H/H center dot center dot center dot N (16.9%) interactions are the most important contributions.