In the title N-Mannich bases, 3-(adamantan-1-yl)-4-(4-fluoro-phen-yl)-1-[(4-phenyl-piperazin-1-yl)meth-yl]-4,5-di-hydro-1H-1,2,4-triazole-5-thione (C29H34FN5S) (I), and 3-(adamantan-1-yl)-4-(4-fluoro-phen-yl)-1-{[4-(2-meth-oxyphen-yl)piperazin-1-yl]-meth-yl}-4,5-di-hydro-1H-1,2,4-triazole-5-thione (C30H36FN5OS) (II), fluoro-phenyl, adamantane and piperazine moieties are linked to a planar triazole ring. There is an additional phenyl ring on the piperazine ring in (I) and a meth-oxy-phenyl ring in (II). In compound (I), the fluoro-phenyl and phenyl rings are inclined to the triazole ring by 86.55 (13) and 60.52 (12)°, respectively, and the two aryl rings are inclined to one another by 66.37 (13)°. In compound (II), the corresponding dihedral angles are 83.35 (13), 71.38 (15) and 11.97 (16)°, respectively. The crystal structure of (I) shows pairs of C-H⋯F hydrogen bonds forming inversion dimers, while in the crystal of compound (II), in addition to the C-H⋯F hydrogen bonds that generate chains parallel to the b axis, there are C-H⋯π inter-actions present that link the chains to form layers parallel to the ab plane.
Keywords: 1,2,4-triazole-5-thione; C—H⋯F hydrogen bonding: C—H⋯π interactions; N-Mannich bases; adamantane; biological activity; crystal structure; piperazine.