Muon spin rotation spectroscopy is a powerful tool that helps scientists understand how materials behave at the atomic level.
Muons are tiny particles, like protons, but lighter. When added to a material, it interacts with its magnetic fields. This helps scientists learn about the material’s structure and behavior, especially for reactive particles like radicals.
A team of researchers, led by Associate Professor Shigekazu Ito from the Institute of Science Tokyo, used µSR spectroscopy to study a specific chemical compound containing phosphorus similar to a common chemical structure.
In µSR spectroscopy, a unique particle called muonium (Mu) is formed when a muon captures an electron. This muonium reacts with the phosphorus compound, creating a highly reactive radical at the phosphorus site.
This reaction is very specific because the phosphorus atom is highly reactive. The study showed that the muon only reacts with the phosphorus atom, forming a stable but highly reactive radical.
The team used transverse-field µSR (TF-µSR) spectroscopy to study this reaction in detail. The muoniation reaction worked efficiently even in low concentrations, producing measurable signals.
Ito et al. (2025) | Scientific Reports | 10.1038/s41598-024-84611-w
Ito said, “By utilizing µSR spectroscopy, we could observe the regioselective muoniation process in detail, providing direct evidence of the reactive nature of phosphorus in this structure. The ability to study this radical at low concentrations opens up new possibilities for investigating reactive species in various molecular systems.”
The researchers used density functional theory (DFT) to study how the muoniated radical (a specific type of compound) is structured and stable. They also examined certain measurements (Aμ and A31P) to understand their electronic structure and stability.
Their calculations showed that the compound stays stable in a flat form, which stops it from becoming a less stable twisted shape.
The study also found that the measurements (Aµ and A31P) decreased as the temperature increased, meaning the radical became more stable. These findings were confirmed by more experiments using µSR and muon level-crossing resonance techniques, which gave more details about the radical’s structure and behavior.
Professor Ito noted that these findings offer valuable insights into the dynamics and structural changes of the mounted radical, which could help future research on radical behavior and stabilization.
When there is less strain, the molecular structure becomes more stable and reactive. This improves the material for practical uses, such as creating electron-spin functional materials and controlling nucleic acids, which are important for advanced technologies and medical applications.
The reaction studied, where muons are added to a compound, has potential benefits in materials science and biology. It could help create new materials for electron-spin functions and substances that regulate nucleic acids.
Overall, this study enhances the understanding of phosphorus-containing radicals and shows how useful µSR spectroscopy is for studying reactive materials at the atomic level.
Journal Reference:
- Shigekazu Ito et al., Muon spectroscopy of a 12-phosphatetraphene with extremely efficient radical trapping properties, Scientific Reports (2025). DOI: 10.1038/s41598-024-84611-w
Source: Tech Explorist
