Tuning of coordination behavior of thiosulfate ion by organic linkers in cadmium thiosulfate compounds

• New inorganic-organic hybrid cadmium thiosulfate compounds have been prepared.
• The coordination behavior of inorganic ligand is triggered by organic ligand.
• Molecular structures are stabilized by hydrogen bonds and π⋯π interactions.
• Investigations lead to understand structural modifications by ligand variations.

Three new inorganic-organic hybrid molecular cadmium thiosulfate compounds, [Cd(S2O3) (C3H10N2)2], I, [Cd2(C10H8N2)4(S2O3)2](C10H8N2)·2H2O, II and [Cd2(C10H8N2)2(H2O)2(S2O3)2](C10H8N2)·2H2O, III have been synthesized using different organic linkers as co-ligand and characterized them thoroughly. The compounds have connectivity between the Cd-centers, the thiosulfate units and the organic ligands forming molecular (zero-dimensional) structures. The ligating behaviors of thiosulfate unit have been triggered by organic linkers. The coordination number of thiosulfate ion to the metal ion can also be enhanced by varying the aromatic ligands instead of aliphatic ligand. The molecular structures are stabilized and formed three-dimensional packing structures through extensive hydrogen bonds and van der Waals interactions. The free aromatic bipyridine ligands are observed in the crystal structures II and III. The unique type of π⋯π interactions play an important role for the stabilization of these two structures. Theoretical studies also revealed that the value of π⋯π interactions are comparable with the classical hydrogen bond interactions. The present study illustrates the usefulness of the organic linkers for the structural modifications in inorganic-organic hybrid compounds.

Figure optionsDownload as PowerPoint slide