A WILL-O鈥�-THE-WISP of the chemical world has been captured by chemists at the
University of Southampton. They managed to trap a 鈥渉ydrogen radical鈥�, the
elusive partner of the better-known hydroxyl radical formed when water splits.
Hydroxyl radicals damage living tissue, but hydrogen radicals react quickly
either with oxygen or with other hydrogen radicals. 鈥淭hey鈥檙e actually hydrogen
atoms,鈥� explains Peter Birkin, who led the team.
The researchers created the radicals in the tiny, transient bubble cavities
that form when ultrasound passes through water. They then ensnared them with a
copper ion and detected the combination electrochemically (Chemical
Communications 2001, p 2230). 鈥淲e have to infer we detected the radical
indirectly through these reactions,鈥� says Birkin.