Synthesis, structures, redox properties, and theoretical calculations of thiohalide capped octahedral hexanuclear...

Area of Science:

• Inorganic Chemistry
• Materials Science
• Coordination Chemistry

Background:

• Hexanuclear technetium clusters are of interest due to their unique electronic structures.
• Previous research has focused on technetium clusters with simpler ligand environments.

Purpose of the Study:

• To synthesize and characterize novel thiohalide-capped octahedral hexanuclear technetium clusters.
• To investigate the structural and electronic properties of these new technetium complexes.
• To compare the properties of technetium clusters with their rhenium analogues.

Main Methods:

• Synthesis of novel technetium-sulfide-halide clusters.
• Single-crystal X-ray diffraction for structural determination.
• Density Functional Theory (DFT) calculations for electronic structure analysis.

Main Results:

• Successfully synthesized and characterized three new thiohalide-capped octahedral hexanuclear technetium clusters: [Tc-S7Br]3-, [Tc-S6Br2]2-, and [Tc-S7Cl]3-.
• Determined the crystal structures, revealing specific Tc-Tc bond distances and disordered capping ligands.
• Observed linear correlations between Tc-S/Br bond distances and capping bromide occupancies.
• Identified one-electron reduction waves indicating Tc/TcII Tc processes.
• DFT calculations showed a smaller HOMO-LUMO energy gap in technetium clusters compared to rhenium analogues.

Conclusions:

• The novel technetium clusters represent the first examples of their kind with thiohalide capping ligands.
• Structural and electronic properties are influenced by the capping ligands.
• Technetium clusters exhibit distinct electronic transitions compared to rhenium analogues, suggesting potential applications in materials science.