Ir3Ge20: A 3n-Connected Cloverleaf-Shaped Supercluster

TL;DR

This paper reports the discovery and analysis of a novel iridium-germanium supercluster with a unique cloverleaf shape, revealing insights into bonding, stability, and aromaticity in cluster-based materials.

Contribution

It introduces a new IrGe12 building block and the Ir3Ge20 supercluster, advancing understanding of intermetallic bonding and nanoscale architecture.

Findings

Identification of IrGe12 as a new building block

Ir3Ge20 exhibits aromaticity and stability

The supercluster follows the 5n rule with 100 valence electrons

Abstract

Group 14 Zintl clusters are promising molecular building blocks for nanoscale architecture. Endohedral variants, which encapsulate d/f-block metals within p-block semimetal cages, provide insights into intermetallic bonding and compound formation. In this study, experimental photoelectron spectroscopy and first-principles calculations were used to investigate the Ir-doped germanium cluster species. A new C2v symmetric building block, IrGe12, was identified, serving as the basis for designing the supercluster Ir3Ge20 with a cloverleaf-shaped, D3h symmetric architecture. This structure consists of three interconnected aromatic IrGe12 units linked by Ge-Ge sigma bonds, forming shielding cones. Ir3Ge20 follows the 5n rule with 100 valence electrons, featuring a core-Ir3 unit with a d10 closed-shell configuration sharing electrons with the Ge20 skeleton. The stability, chemical bonding, and aromaticity of Ir3Ge20 were confirmed, demonstrating a novel approach to precise atom manipulation in cluster-based materials and devices.