How 'asymmetric alloying' is creating the next generation of luminescent materials

Metal cluster molecules are discrete compounds containing multiple metal atoms held together by metal–metal and metal–ligand bonding. They serve as excellent candidates for catalysts, biosensors, and even for drug development. Developing atomic-level molecular editing methods for such metal clusters remains an important challenge and represents a promising strategy for expanding their structural and functional diversity. Such approaches can enable structure-specific properties, high near-infrared (NIR) photoluminescence quantum yields, and unique reactivities and electronic structures.

Alloying is a powerful method for achieving this goal. In this regard, a key challenge is asymmetric alloying, which introduces asymmetry into the metal cluster by selectively placing heterometal atoms at non-equivalent sites, desymmetrizing the cluster and therefore imparting chirality-associated functionality. Moreover, highly selective asymmetric synthesis methods for heterometallic clusters are expected to contribute significantly to the development of chiroptical materials. However, methods capable of achieving such controlled asymmetric synthesis have rarely been reported.

In a new study, a research team led by Professor Mitsuhiko Shionoya of the Research Institute for Science and Technology at Tokyo University of Science (TUS), Japan, has successfully demonstrated an asymmetric alloying method, creating asymmetric polyhedrons of carbon-centered gold(I)-silver(I) ion clusters. “Through asymmetric synthesis, we have created a carbon-centered gold(I)-silver(I) chiral bicapped square antiprism polyhedral cluster. This approach also enables enantioselective structural control,” explains Prof. Shionoya. “Moreover, the obtained clusters exhibit phosphorescence and distinct chirality-dependent properties that are important for chiral sensing applications.” The team also included Professor Masahiro Ehara from the Research Center for Computational Science, Institute for Molecular Science and SOKENDAI, Japan, as well as Professor Zhen Lei of the Fujian Provincial Key Laboratory of Advanced Inorganic Oxygenated Materials, College of Chemistry, Fuzhou University, China. Their study will be published in the journal Nature Communications on June 5, 2026.

To explore asymmetric alloying, the researchers selected a highly symmetric carbon(C)-centered hexagold(I) cluster (CAu^I₆), with a well-defined octahedral structure. According to their previous studies, the researchers found that this compound has suitable reactivity, high stability, and a prochiral structure, representing a great candidate chiral framework for the study.

The researchers found that the addition of silver trifluoroacetate to a triphenylphosphine-protected CAu^I₆ cluster produced a chiral-at-carbon hexasilver(I)-alloyed tetragoldmethane (CAu^I₄Ag^I₆) cluster through etching of two gold(I) atoms. Single-crystal X-ray structure analysis showed a chiral arrangement of gold(I) and silver(I) atoms around the central carbon atom and a bicapped square antiprism structure.

Notably, the researchers also demonstrated selective asymmetric synthesis of CAu^I₄Ag^I₆ enantiomers using specific optically active homochiral carboxylate ligands. Furthermore, each enantiomer exhibited red-to-NIR phosphorescence and distinct chiroptical activity, including circular dichroism and Circularly Polarized Luminescence.

The researchers further probed the binding properties of the clusters through computational analyses, revealing how the C–Au^I bonds and the C^…Ag^I interactions contribute to their unique electronic structure and chirality.

“Our approach represents a novel pathway for controlling the structure of metal ion clusters by introducing suitable heterogeneous metal ions and asymmetric synthesis accompanied by atomic-level etching,” remarks Prof. Shionoya. “This will pave the way for the creation of chiral luminescent nanomaterials and can potentially contribute greatly to the field of photofunctional materials.”

This innovative strategy establishes a new paradigm for precise alloying and stereocontrol of metal clusters at the atomic level, with potential implications for a wide range of functional materials applications.

Reference

DOI: https://doi.org/10.1038/s41467-026-72787-w

Authors: Xiao-Li Pei¹, Pei Zhao², Wen-Ting Liu³, Hitoshi Ube¹, Zhen Lei³, Masahiro Ehara², and Mitsuhiko Shionoya¹

Affiliations:
¹Research Institute for Science and Technology, Tokyo University of Science, Japan

²Research Center for Computational Science, Institute for Molecular Science and SOKENDAI, Japan

³Fujian Provincial Key Laboratory of Advanced Inorganic Oxygenated Materials, College of Chemistry, Fuzhou University, China

Funding information

This work was supported by JSPS KAKENHI Grant Numbers JP22K14691 (Xiao-Li Pei), Grant Numbers JP24K08443 (Xiao-Li Pei), JSPS KAKENHI Grant Numbers JP24K17663 (Pei Zhao), JSPS KAKENHI Grant Numbers JP22H05133 (Masahiro Ehara), JSPS KAKENHI Grant Numbers JP21H05022 (Masahiro Ehara), MEXT KAKENHI Grant Number JP16H06509 (Mitsuhiko Shionoya), JST, CREST Grant Number JPMJCR22B2 (Mitsuhiko Shionoya), Japan.

Further information

Professor Mitsuhiko Shionoya
Research Institute for Science and Technology
Tokyo University of Science, Japan
Email: shionoya@rs.tus.ac.jp

Professor Masahiro Ehara
Institute for Molecular Science and SOKENDAI, Japan
Email: ehara@ims.ac.jp

Dr. Xiao-Li Pei
Research Institute for Science and Technology
Tokyo University of Science, Japan
Email: pei@rs.tus.ac.jp