Scientists have developed a new way to precisely modify unusual boron-rich molecules called carboranes, a breakthrough that could help improve cancer treatments, chemical sensors, and advanced glowing materials.
The research was carried out by teams from the University of Barcelona, the University of Girona, and Nanjing University. Their findings were published in Angewandte Chemie International Edition.
Carboranes are cage-shaped molecules made from carbon, boron, and hydrogen atoms. They are extremely stable and can withstand high temperatures and radiation.
Because of their unique electronic properties, researchers have become increasingly interested in using them in medicine, materials science, and chemical technology.
One of the most promising medical uses involves boron neutron capture therapy, or BNCT, an experimental cancer treatment designed to target tumor cells very precisely.
In this therapy, boron-containing compounds accumulate inside cancer cells. When exposed to neutrons, the boron atoms trigger reactions that destroy the tumor from within while minimizing damage to nearby healthy tissue.
However, scientists have struggled to chemically modify carboranes in useful ways. The challenge comes from the molecule’s structure. Carboranes contain many boron-hydrogen bonds that are extremely similar to one another, making it difficult to selectively change specific parts of the molecule.
The new study offers a solution to that long-standing problem.
The research team developed a metal-free chemical method that uses special iodine-based compounds called hypervalent iodine reagents to selectively activate certain boron-hydrogen bonds under mild conditions.
This allowed the scientists to create new types of chemical bonds involving boron and other elements, including oxygen, nitrogen, sulfur, and phosphorus.
According to Jordi Poater, the discovery gives chemists a new and flexible tool for designing advanced boron-based molecules.
The researchers also identified a previously unknown interaction between iodine and the boron cage structure. This interaction helps explain why the reactions can target very specific positions within the molecule, something that was difficult to achieve using older techniques.
The new method builds on earlier research from the same team that discovered a unique “migration” process inside the boron cage. That earlier finding showed that chemical groups could move within the structure, allowing scientists to reach positions that had previously been inaccessible.
Together, these discoveries could greatly expand the range of possible applications for carboranes.
The researchers have already used the new technique to create boron-containing compounds with promising medical and technological uses. Some may eventually improve boron neutron capture therapy for cancer, while others could be used in luminescent materials that glow under certain conditions, detect oxygen, or generate reactive oxygen species for specialized chemical and biomedical applications.
Because the new method avoids the use of metal catalysts, it may also be simpler, cleaner, and potentially more environmentally friendly than traditional chemical approaches.
The scientists say the breakthrough opens the door to designing a new generation of boron-based molecules with highly customizable properties for medicine, sensing technologies, and advanced materials.
