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In nanoscale chemistry, magic-sized clusters (MSCs) stand out for their precise atomic configurations and privileged stability, offering unprecedented insights into the atomic-level structure of ligand-capped nanocrystals and a gateway to new synthesis and functionality. This article explores our efforts to shed light on the structure and reactivity of II-VI and III-V semiconductor MSCs. We have specifically been interested in the synthesis, isolation, and characterization of MSCs implicated as key intermediates in the synthesis of semiconductor quantum dots. Our exploration into their synthesis, structure, transformation, and reactivity provides a roadmap to expand the scope of accessible semiconductor clusters with diverse structures and properties. It paves the way for tailor-made nanomaterials with unprecedented atom-level control. In these studies, atomic level structure has been deduced through advanced characterization methods, including single-crystal and powder X-ray diffraction, complemented by pair distribution function analysis, nuclear magnetic resonance spectroscopy, and vibrational spectroscopy. We have identified two distinct families of CdSe MSCs with zincblende and wurtzite-like structures. We have also characterized two members of the wurtzite-like family of InP clusters and a related InAs cluster. Our research has revealed intriguing structural homologies between II-VI and III-V MSCs. These findings contribute to our fundamental understanding of semiconductor MSCs and hint at broader implications for phase control at the nanoscale and the synthesis of novel nanomaterials. We have also explored three distinct pathways of cluster reactivity, including cluster interconversion mediated by controlling the chemical potential of the reaction environment, both seeded and single source precursor growth mechanisms to convert MSCs into larger nanostructures, and cation exchange to access new cluster compositions that are precursors to nanocrystals that may be challenging or impossible to access from traditional bottom-up nucleation and growth. Together with the collective efforts of other researchers in the field of semiconductor cluster chemistry, our work establishes a strong foundation for predicting and controlling the form and function of semiconductor MSCs. By highlighting the role of surface chemistry, stoichiometry, and dopant incorporation in determining cluster properties, our work opens exciting possibilities for the design and synthesis of new materials. The insights gained through these efforts could significantly impact the future of nanotechnology, particularly in areas like photonics, electronics, and catalysis.
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This content will become publicly available on September 23, 2026
Sequential Cation Exchange in Indium Phosphide Magic-Sized Clusters
Semiconductor nanomaterials with complex compositions have emerged as next-generation materials for applications in catalysis, energy storage, and sensing. Despite achieving high-quality doped II–VI and III–V semiconductor nanocrystals in specific cases, a general approach to compositional control is lacking. Leveraging the metastability of semiconductor magic-sized clusters (MSCs), we demonstrate a general approach to sequential cation exchange under mild conditions. The sequential exchange begins with In37P20(O2CC13H27)51 MSCs and proceeds through a copper-doped intermediate to achieve Mn-, Co-, Fe-, and Mo-doped clusters at ambient temperature. The resulting products are spectroscopically and structurally characterized to track changes in absorbance, composition, and size. Moreover, we use these doped clusters as seeds for the growth of doped InP nanocrystals, and in doing so, we find that the cluster dopant can be preserved throughout the growth process, resulting in different degrees of incorporation depending on the dopant identity. Finally, the addition of tributylphosphine and mild heating were employed as postsynthetic strategies to remove Cu impurities in the final doped nanocrystals. This mild approach for transition metal doping of MSCs through a sequential cation exchange reaction offers a versatile route toward doped and multicomponent nanocrystals.
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- PAR ID:
- 10682754
- Publisher / Repository:
- American Chemical Society
- Date Published:
- Journal Name:
- Chemistry of Materials
- Volume:
- 37
- Issue:
- 18
- ISSN:
- 0897-4756
- Page Range / eLocation ID:
- 7287 to 7297
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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