Israeli Scientist Solves 200-Year-Old Chemistry Problem

By Hamodia Staff

YERUSHALAYIM — How does a proton move through water?

The 200-year-old question was never answered conclusively until Prof. Ehud Pines of Ben-Gurion University of the Negev’s Department of Chemistry​​ recently proved how it’s done.

In 1806, Theodor Grotthuss proposed what became known as the Grotthuss Mechanism. It was accepted as the standard textbook solution, though experts in the field were aware of its flaws.

Seventeen years of research by Pines and colleagues yielded the correct solution: that the proton moves through water in trains of three water molecules. The proton train “builds the tracks” underneath them for their movement and then disassembles the tracks and rebuilds them in front of them to keep going. It’s a loop of disappearing and reappearing tracks that continues endlessly.

Similar ideas were put forward by a number of scientists in the past, but according to Pines, they were not assigned to the correct molecular structure of the hydrated proton, which by its unique trimeric structural properties leads to promoting the Grotthuss mechanism. 

The experimental studies underpinning the new explanation were replicated by another research group, as reported in a cover story in Angewandte Chemie, journal of the German Chemical Society.

“The debates on the Grotthuss mechanism and the nature of proton solvation in water have grown heated,” said Pines, “as this is one of the most basic challenges in chemistry. Understanding this mechanism is pure science, pushing the boundaries of our knowledge and changing one of our fundamental understandings of one of nature’s most important mass and charge transport mechanisms.”