The characteristics of oxygen in acetic acid

Atoms incorporated in molecules get a kind of ‘chemical personality’. Christian Ott, Thomas Pfeifer and their team from the Max Planck Institute for Nuclear Physics are interested in this ‘chemical personality’ of the two oxygen atoms of acetic acid. The colourless liquid is not only used at home for salads, but also in the food and chemical industries. At the SQS instrument of European XFEL, they selectively excite the electrons orbiting either one or the other of the respective oxygen atoms with X-ray flashes and measure with further X-ray pulses that follow shortly afterwards how excitation energy propagates between them in the molecules, within femtoseconds and below. In a way they measure how excitation affects the ‘chemical personality’ of the oxygen atoms. This experiment could shed light on the fundamental nature of organic acids in general, as the same arrangement of oxygen atoms is found in all of them.