Three anilides of 2,2′-thiodibenzoic acid

The structures of N,N′-bis-(2-methylphenyl)-2,2′- thiodibenzamide, C₂₈H₂₄N₂O₂S, (Ia), N,N′-bis-(2-ethyl-phenyl)-2,2′-thiodibenzamide, C₃₀H ₂₈N₂O₂S, (Ib), and N,N′-bis-(2- bromophenyl)-2,2′-thiodibenzamide, C₂₆H₁₈Br ₂N₂O₂S, (Ic), are com-pared with each other. For the 19 atoms of the consistent thiodibenzamide core, the r.m.s. deviations of the molecules in pairs are 0.29, 0.90 and 0.80 Å for (Ia)/(Ib), (Ia)/(Ic) and (Ib)/(Ic), respectively. The conformations of the central parts of molecules (Ia) and (Ib) are similar due to an intra-molecular N - H⋯O hydrogen-bonding interaction. The molecules of (Ia) are further linked into infinite chains along the c axis by intermolecular N - H⋯O interactions, whereas the molecules of (Ib) are linked into chains along b by an inter-molecular N - H⋯π contact. The conformation of (Ic) is quite different from those of (Ia) and (Ib), since there is no intramolecular N - H⋯O hydrogen bond, but instead there is a possible intramolecular N - H⋯Br hydrogen bond. The molecules are linked into chains along c by intermolecular N - H⋯O hydrogen bonds.