In a first, researchers capture fleeting 'transition state' in ring-shaped molecules excited by light

Using a high-speed "electron camera" at the Department of Energy's SLAC National Accelerator Laboratory and cutting-edge quantum simulations, scientists have directly imaged a photochemical "transition state," a specific configuration of a molecule's atoms determining the chemical outcome, during a ring-opening reaction in the molecule α-terpinene. This is the first time that scientists have precisely tracked molecular structure through a photochemical ring-opening reaction, triggered when light energy is absorbed by a substance's molecules.