Bis(Vinylenedithio)-Tetrathiafulvalene-Based Coordination Networks.

Area of Science:

• Materials Science
• Chemistry
• Solid State Physics

Background:

• Coordination polymers incorporating electroactive molecules are crucial for developing porous conducting materials.
• Tetrathiafulvalene (TTF) based metal-organic frameworks have shown promise for through-space conductivity.
• Sulfur-enriched scaffolds for such applications remain underexplored.

Purpose of the Study:

• To synthesize and characterize novel coordination polymers using a sulfur-rich bis(vinylenedithio)-tetrathiafulvalene (BVDT-TTF) ligand functionalized with pyridine.
• To investigate the impact of chemical oxidation on the conductivity of these novel networks.
• To elucidate the electronic structure and conduction mechanism of the synthesized materials.

Main Methods:

• Synthesis of coordination polymers using BVDT-TTF and various transition metals.
• Chemical oxidation using iodine.
• Single-crystal to single-crystal X-ray diffraction for structural analysis.
• Raman spectroscopy and Density Functional Theory (DFT) calculations for electronic structure determination.
• Band structure calculations to assess conductivity.

Main Results:

• Four isostructural coordination polymer networks were successfully synthesized.
• Conductivity of the networks significantly increased upon iodine-induced chemical oxidation.
• Single-crystal X-ray diffraction confirmed oxidation in the Cd(II) polymer.
• DFT and Raman spectroscopy confirmed the oxidation state and electronic properties.
• Band structure calculations revealed a 2D conduction mechanism from an antiferromagnetic ground state.

Conclusions:

• The study demonstrates the successful incorporation of sulfur-enriched BVDT-TTF ligands into coordination polymers.
• Chemical oxidation with iodine effectively enhances the conductivity of these materials.
• These findings offer insights into designing improved through-space conducting frameworks using sulfur-rich ligands.