Crystal structures and Hirshfeld surface analysis of 2-(adamantan-1-yl)-5-(4-fluorophenyl)-1,3,4-oxadiazole and 2-(adamantan-1-yl)-5-(4-chlorophenyl)- 1,3,4-oxadiazole

Abstract

The crystal structures of the title adamantane-oxadiazole hybrid compounds, C18H19FN2O (I) and C18H19ClN2O (II), are built up from an adamantane unit and a halogenophenyl ring, [X = F (I), Cl (II)], in position 5 on the central 1,3,4-oxadiazole unit. The molecular structures are very similar, only the relative orientation of the halogenophenyl ring in comparison with the central five-membered ring differs slightly. In the crystals of both compounds, molecules are linked by pairs of C - H⋯N hydrogen bonds, forming inversion dimers with R 2 2(12) ring motifs. In (I) the dimers are connected by C - H⋯F interactions, forming slabs lying parallel to the bc plane. In (II), the dimers are linked by C - H⋯π and offset π-π interactions [interplanar distance = 3.4039(9)Å], forming layers parallel to (10 ).