(4-Fluoro-phen-yl)thio-urea-1,10-phenanthroline (1/1)

Refluxing a mixture of 1,10-phenanthroline, (4-fluoro-phen-yl)thio-urea and cadmium(II) chloride did not produce the expected mixed-ligand complex but formed a co-crystal of the two ligands, C12H8N2·C7H7FN2S. The asymmetric unit consists of two pairs of the co-crystal mol-ecules. In each (4-fluoro-phen-yl)thio-urea mol-ecule, the planes of the N2CS thio-urea units are almost perpendicular to the corresponding fluoro-benzene rings, subtending angles of 76.53 (7) and 85.25 (7)°. In the crystal, N-H⋯N and N-H⋯S hydrogen bonds form inversion dimers from the co-crystal pairs. A weak π-π inter-action between the phenanthroline rings [centroid-centroid distance = 3.7430 (15)Å] is also observed.