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.
@article{arxiv.2601.03524,
title = {Ir3Ge20: A 3n-Connected Cloverleaf-Shaped Supercluster},
author = {Xue Wu and Wen-Shuai Dai and Lulu Li and Fangying Hao and Hong-Guang Xu and Wei-Jun Zheng and Jijun Zhao},
journal= {arXiv preprint arXiv:2601.03524},
year = {2026}
}