Ab initio study of thiolate-protected Au102 nanocluster

Area of Science:

• * Computational chemistry and materials science.
• * Nanoparticle synthesis and characterization.
• * Electronic structure theory.

Background:

• * The structural determination of the Au(102)(p-MBA)(44) nanocluster has been achieved through crystallization.
• * This nanocluster exhibits a complex multilayered structure: Au(54)(penta-star)@Au(38)(ten wings)@Au(10)(two pentagon caps).
• * Understanding the factors contributing to the high stability of such nanoclusters is crucial.

Purpose of the Study:

• * To investigate the electronic properties of gold nanoclusters using ab initio calculations.
• * To elucidate the origins of the high stability of the Au(102)(p-MBA)(44) nanocluster.
• * To compare the electronic structures of Au(102)(SCH(3))(44), Au(102)(SCH(3))(42), and Au(104)(SCH(3))(46) nanoclusters.

Main Methods:

• * Performed ab initio calculations to study electronic properties.
• * Focused on gold nanoclusters with varying ligand and core structures.
• * Analyzed the highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) gaps.

Main Results:

• * Au(102)(SCH(3))(44) nanocluster exhibits a HOMO-LUMO gap of approximately 0.54 eV.
• * Au(104)(SCH(3))(46) nanocluster shows a comparable HOMO-LUMO gap of approximately 0.51 eV.
• * Au(102)(SCH(3))(42) nanocluster displays a zero HOMO-LUMO gap, indicating instability.

Conclusions:

• * The high stability of Au(102)(p-MBA)(44) is partly attributed to electronic shell closing.
• * An effective 58 valence electrons contribute to the stability, analogous to other stable gold clusters.
• * Computational electronic structure analysis provides insights into nanocluster stability.