Dopant-Dependent Electronic Structures Observed for M₂Au₃₆(SC₆H₁₃)₂₄ Clusters (M = Pt, Pd)

Area of Science:

• Nanomaterials Science
• Inorganic Chemistry
• Physical Chemistry

Background:

• Heteroatom doping is a key strategy for tuning the properties of atomic-level gold clusters.
• Understanding structure-property relationships in doped gold clusters is crucial for developing new functional materials.

Purpose of the Study:

• To investigate the effects of platinum (Pt) and palladium (Pd) doping on the electronic and optical properties of Au38 clusters.
• To elucidate the structural and electronic consequences of incorporating Pt and Pd into the Au38 core.

Main Methods:

• Synthesis of core-doped [Pt2Au36(SC6H13)24]2− and [Pd2Au36(SC6H13)24]0 clusters.
• Voltammetric analysis to determine electronic structures and HOMO-LUMO gaps.
• Density functional theory (DFT) investigations for theoretical validation.
• Geometric analysis of doped cluster structures.

Main Results:

• Pt and Pd doping leads to distinct electronic structures in Au38 clusters.
• [Pt2Au36(SC6H13)24]2− exhibits a HOMO-LUMO gap of 0.95 V.
• [Pd2Au36(SC6H13)24]0 shows a significantly reduced HOMO-LUMO gap of 0.26 V, indicative of Jahn-Teller distortion.
• DFT calculations confirm the reduced gap in Pd-doped clusters.
• Pd doping causes flattening of the M2Au21 core in the 12-electron cluster.
• Reversible geometric interconversion between oxidation states of Pt-doped clusters was observed.

Conclusions:

• Heteroatom doping provides precise control over the electronic and optical properties of gold clusters.
• Pd doping induces significant electronic and geometric modifications, including Jahn-Teller distortion.
• The oxidation state of Pt-doped clusters influences their geometry, allowing for reversible interconversion.