Molecular Physics seminar

Introducing a New Concept to Understand Excited State Dynamics in Polyenes: The Dynamophore

by Dr Oliver Schalk (Chemical Physics, SU)

FA31 ()


Excited state dynamics of larger systems such as biomolecules followed upon light irradiation are very complex and, despite much effort, many systems are still far from being understood. Even the dynamics of small sub-units such as the DNA-bases turn out to be highly complex. In order to disentangle the underlying dynamics, a set of rules that allow for prediction of molecular dynamics would be crucial. A first step toward such rules will be presented in this talk on the important molecular class of polyenes (unsaturated hydrocarbons). By definition, UV- and vis-photons are absorbed by a chromophore which constitutes the part of a molecule where the electronic transition for a given spectral band is localized. However, dynamics induced by these photons may take place in another, localized region of the molecular framework which is defined as dynamophore. Here, we present time-resolved photoelectron studies combined with ab initio calculations on various polyenic systems to show how localization leads to a small subset of dynamophores and the consequences of this behavior. At the end, we give an outlook on the next step which is working toward rules for molecules which possess more than just carbon and hydrogen atoms.