Revolutionizing Hydrogen Fluoride Synthesis: Scalable and Safer Generation

Researchers use cation exchange to generate hydrogen fluoride and a range of new fluorinating complexes

Hydrogen fluoride (HF) is the simplest and cheapest fluorinating reagent available, but its volatility and toxicity limit its practical use. Now, researchers from Shibaura Institute of Technology, Japan, introduce a new approach for the generation of HF, which is both safe and scalable. Using the cation exchange method between potassium fluoride (KF) and Amberlyst 15DRY, they generated HF and converted it to amine-3HF complexes, thereby expanding the range of accessible complexes for fluorination reactions.

 

Fluorine-based compounds are everywhere—from life-saving pharmaceuticals and crop protection agents to high-performance materials like Teflon and refrigerants. Thanks to their unique chemical properties, which make them indispensable across various industries. But synthesizing these compounds has long been a challenge due to the hazardous and toxic fluorinating reagents.

 

Hydrogen fluoride (HF) is one such reagent that is effective and inexpensive, but its high toxicity and corrosive nature make it extremely difficult to handle. In a recent breakthrough, researchers led by Professor Toshiki Tajima from Shibaura Institute of Technology, Japan, have developed a groundbreaking method to safely and efficiently generate HF from simple and stable materials—unlocking a safer path to fluorination chemistry. The study, made available online on April 22, 2025, and published in Volume 31, Issue 32 of the journal Chemistry – A European Journal on June 6, 2025,  unveils a cation exchange method to safely generate HF on demand.

 

Cation exchange reactions are chemical processes where positively charged ions are swapped between a solid porous material (usually a resin) and a salt solution. In the current study, the researchers used Amberlyst 15DRY, a commercially available solid acid resin, as the cation exchange resin and potassium fluoride (KF), which is a stable and inexpensive salt. By combining these solids in acetonitrile, they triggered a cation exchange reaction, which resulted in the quantitative production of HF without any external hazards.

 

“In a single step of the cation exchange reaction, we only generated 69% of HF from KF. But by removing the HF after each run and repeating the reaction seven times, we achieved nearly complete HF production from KF conversion,” explains Prof. Tajima.

 

 

Once the reaction was complete, HF was separated from the resin, and organic amines were added to the HF solution in a 1:3 ratio. HF was immediately captured by these organic amines to form stable amine-3HF complexes. The complexes were then isolated by evaporating the solvent under reduced pressure. Amine-3HF complexes commonly act as nucleophilic fluorinating agents, i.e., these complexes donate fluoride ions (F?) to other molecules while replacing another negatively charged leaving group (nucleophile) from those molecules. 

 

These fluorination reactions are especially valuable for various applications in industries.
“Various HF complexes can be derived from HF,” notes Prof. Tajima. “These complexes act as fluorinating agents and could enable the synthesis of novel pharmaceuticals, functional materials, and even molecular probes.” 

 

What sets this study apart is that it eliminates the use of pressurized HF gas and corrosive liquid reagents, making the process safer and 欧洲杯足彩app下载_欧洲杯下注平台-【直播*网站】 aligned with green chemistry principles. Also, the method operates under ambient conditions with common laboratory reagents without the use of any special equipment, making it suitable for both laboratory and industrial scales. Moreover, the resin used for the cation exchange reaction was effectively reused for almost over 10 times, marking the efficiency and sustainability of the approach.

The study marks a significant milestone in fluorination chemistry, opening avenues for multiple applications across various industries. The new fluorinating agents generated through the complexation could open multiple avenues for unique applications in pharmaceuticals, agrochemicals, and material sciences, all while ensuring a simpler, safer, and sustainable process of fluorination.

 

 

Reference

Title of original paper:	Quantitative Generation of HF from KF and Formation of Amine-3HF Complexes by Using Cation Exchange Reaction Between KF and Amberlyst 15DRY
Journal:	Chemistry – A European Journal
DOI:	10.1002/chem.202500789

Additional infotmation for EurekAlert

Latest Article Publication Date:	06 June 2025
Method of Research:	Experimental Study
Subject of Research:	Not Applicable
Conflicts of Interest Statement:	Not Applicable

Authors

About Professor Toshiki Tajima from SIT, Japan

Dr. Toshiki Tajima is a Professor at the College of Engineering, Shibaura Institute of Technology, Japan. He earned his doctorate from the Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, and specializes in organic electrochemistry and synthesis. He has over 56 peer-reviewed publications and over 11 book chapters to his credit. His research mainly focuses on green chemistry, environmental chemistry, and sustainable sciences.

   

Funding Information

This work was supported by JSPS KAKENHI Grant Numbers JP19K05567 and JP22K05197.