Watching a Molecule Change its shape

Human vision is based on a molecule, the retinal chromphore, which acts as an optical switch - following the absorption of a photon it undergoes an isomerization. This photoisomerization has remarkable properties - it is highly efficient, specific and fast. In order to understand this mechanism and photoisomerizations in general, we need a tool which allows us to 'see' the shape of an isolated molecule, and observe changes to the shape. These kinds of measurements have recently become possible thanks to developments in the field of ion mobility spectroscopy. In this talk I will survery the technique and present our recent study in which we measured the barrier energy for isomerization of the retinal chromphore. 

“Direct Measurement of the Isomerization Barrier of the Isolated Retinal Chromophore”, J. Dilger, L. Musbat, M. Sheves, A. B. Bochenkova, D. E. Clemmer, Y. Toker, Ang Chemie Int. Ed. 127 (2015), 4830-4834.