Isotypic crystal structures of 1-benzyl-4-(4-bromo­phen­yl)-2-imino-1,2,5,6,7,8,9,10-octa­hydro­cyclo­octa­[b]pyridine-3-carbo­nitrile and 1-benzyl-4-(4-fluoro­phen­yl)-2-imino-1,2,5,6,7,8,9,10-octa­hydro­cyclo­octa­[b]pyridine-3-carbo­nitrile

The mol-ecules of the two isotypic title compounds, C25H24BrN3, (I), and C25H24FN3, (II), comprise a 2-imino-pyridine ring fused with a cyclo-octane ring. In (I), the cyclo-octane ring adopts a twisted chair-chair conformation, while in (II), this ring adopts a twisted boat-chair conformation. The dihedral angles between the planes of the pyridine ring and the bromo-benzene and phenyl rings are 80.14 (12) and 71.72 (13)°, respectively, in (I). The equivalent angles in (II) are 75.25 (8) and 68.34 (9)°, respectively. In both crystals, inversion dimers linked by pairs of C-H⋯N inter-actions generate R 2 (2)(14) loops, which are further connected by weak C-H⋯π inter-actions, generating (110) sheets.