Molecular structure of N,N-bis(benzimidazol-2-ylethyl)sulfide dihydrochloride dihydrate, a heavy metal chelating ligand

The title compound contains two benzimidazole nitrogens and one thioether sulfur atom, which are potential sites for metal ion binding. Both the benzimidazole nitrogens of the molecule are protonated. The benzimidazole rings are almost parallel to each other, the dihedral angle being 6.9(1)degrees. The C-S-C bond angle is 100.6(2)degrees and the C-S-C-C torsion angles are -75.9(3)degrees and -80.6(3)degrees, leading to gauche conformation which is one of the favored conformations in the crystalline state of simple monothioethers.