Investigation of the ultra-fast structural changes in metal-organic complexes: comparison spectroscopy and time-resolved XRD

Our aim is a detailed understanding of the ultrafast structrual dynamics and the underlying basic machanisms of molecular switches under optical excitation, which are still not fully understood in its variety. In order to monitor the occurring structural changes in molecules and alloys we are taking advantage of time-resolved x-ray diffraction measurements. but since the important electronic changes due to optical excitation take place on very short ps- and sub-ps timescales it gives rise to the necessity of faster time resolved measurements than those which are currently possible at third generation synchrotrons. Besides new attempts of directly monitoring the structural changes with shorter x-ray pulses by femtosecond FEL- an XPS-pump-probe experiments, we are currently gaining more insight in the structural dynamics by indirect measurements using our fs-time-resolved transient absorption spectroscopy. Therefore we will present our recent spectroscopic data of a metal-organic complex which will be related to certain structural changes, while the near future aim is to prove these by further x-ray experiments

Crystal structure of trans-1-{2-[4-(di­methyl­amino)­phen­yl]eth­yl}-4-[2-(pyren-1-yl)eth­yl]cyclo­hexa­ne.

The title compound, C34H37N, is a pyrene derivative in which the pyrene ring system is linked to an ethyl­cyclo­hexane unit which, in turn, carries a [4-(di­methyl­amino)­phen­yl]ethyl substituent in the para position. The central cyclo­hexane ring has a chair conformation, with the exocyclic C-C bonds in equatorial orientations. The benzene ring is inclined to the mean plane of the pyrene ring system [maximum deviation = 0.038 (4) Å] by 14.84 (15)°. In the crystal, mol­ecules are linked by C-H...[pi] inter­actions, forming chains propagating along [010]. The crystal was refined as a non-merohedral twin [domain ratio = 0.9989 (4):0.0011 (4)]