(E)-5-(3,5-Dimethyl-phen-yl)-N-[4-(methyl-sulfan-yl)benzyl-idene]-1,3,4-thia-diazol-2-amine.

The title compound, C(18)H(17)N(3)S(2), was synthesized by the reaction of 5-(3,5-dimethyl-phen-yl)-1,3,4-thia-diazol-2-amine and 4-(methyl-sulfan-yl)benzaldehyde. An intra-molecular C-H⋯S hydrogen bond results in the formation of a planar (r.m.s. deviation = 0.003 Å) five-membered ring. In the crystal structure, inter-molecular C-H⋯N hydrogen bonds link the mol-ecules to form layers parallel to (011).

4,5-Diaza-9H-fluoren-9-imine.

In the title compound, C(11)H(7)N(3), the diaza-fluorene rings are almost coplanar with an r.m.s. deviation of 0.0160 Å. In the crystal structure, C-H⋯N hydrogen bonds link mol-ecules into sheets parallel to the ab plane. Mol-ecules are also stacked regularly along the c axis by a variety of π-π inter-actions with centroid-centroid distances in the range 3.527 (2)-3.908 (2) Å.

1-[9-Ethyl-6-(2-methyl-benzo-yl)-9H-carbazol-3-yl]ethanone.

In the title compound, C(24)H(21)NO(2), the pendant benzene ring is inclined at a dihedral angle of 86.66 (18)° with respect to the adjacent aromatic ring of the carbozole unit. In the crystal structure, symmetry-related mol-ecules are linked via C-H⋯O and C-H⋯π inter-actions.