Electrocyclic photochemistry imaged in real space and time

Speaker:  Thomas Wolf, SLAC

Program Description:
Electrocyclic reactions are an important tool in organic synthetic chemistry because of their conformer- and stereo-specificity. Conformer-specific reaction products can be predicted with the help of the famous Woodward-Hoffmann rules. I will present results from our recent investigations of the mechanistic details of electrocyclic ring-opening reactions in a series of six-membered ring molecules using SLAC’s megaelectronvolt ultrafast electron diffraction facility in combination with excited state wavepacket simulations. We were able to image for the first time the evolution of a specific molecular conformer into the product isomer, which is predicted by the Woodward-Hoffmann rules in real space and time. Additionally, our investigations reveal details of the reaction mechanism which go beyond and challenge the simple picture drawn by the Woodward-Hoffmann rules.