First snapshots of ionised water’s fleeting radical–cation pair

By Tom Metcalfe2021-10-12T13:30:00

A backlit, closeup photo of a drop of water as it hits a surface, viewed from below. The drop appears as large circle covering most of the photo, with smaller droplets scattering away from it.

Source: © Getty Images

Ultrafast electron diffraction spots hydroxyl–hydronium complex before it separates a hundred quadrillionth of a second later

For the first time, scientists have imaged and measured a fundamental but fleeting step in water ionisation – the creation of the hydroxyl–hydronium complex OH(H₃O⁺), a radical–cation pair – before it separates a hundred quadrillionths of a second later.