Ligand-Driven Electrochemical Tuning of Co₆Se₈ Chevrel Clusters

Area of Science:

• Inorganic Chemistry
• Materials Science
• Nanotechnology

Background:

• Chevrel-type clusters (Co₆Se₈L₆) are molecular analogues to extended solids and building blocks for hierarchical materials.
• Their solution and optical properties are underexplored, limiting fundamental understanding.
• Establishing structure-property relationships is crucial for advanced material design.

Purpose of the Study:

• To synthesize and characterize a series of Co₆Se₈(P(C₆H₄R)₃)₆ clusters with varying para-substituents (R = Cl, F, H, CH₃, OCH₃).
• To investigate the impact of ligand substitution on the electronic, electrochemical, and structural properties of these clusters.
• To explore the potential of these clusters as components in charge transfer assemblies.

Main Methods:

• Stepwise synthesis of cobalt-selenium Chevrel-type clusters.
• Solution and solid-state experimental characterization.
• Density functional theory (DFT) calculations.
• Cyclic voltammetry (CV) measurements.

Main Results:

• The Co₆Se₈ cores exhibit consistent electronic and structural properties across different para-substituents.
• Cyclic voltammetry reveals significant tunability in electron transfer energetics (spanning ~0.5 V) based on ligand substitution.
• Hammett parameters (σ_p) correlate with observed electrochemical shifts.
• The clusters are structurally robust and electrochemically tunable.

Conclusions:

• Co₆Se₈ clusters can be considered atomically precise nanoclusters.
• Ligand substitution offers a powerful strategy to tune the electrochemical properties of these clusters.
• These findings highlight their potential as building blocks for charge transfer assemblies and advanced functional materials.