Systems Chemistry: From Logic Gates based on Supramolecular Gels to Supramolecular Polymer Transporters Seminar
- Time:
- 15:00
- Date:
- 8 March 2017
- Venue:
- Building 27, Room 2003, Chemistry, University of Southampton
For more information regarding this seminar, please email Steve Goldup at S.Goldup@soton.ac.uk .
Event details
Prof Christoph Shalley presents a seminar as part of the FIMS research group seminar series.
The talk will provide three examples for molecules that cooperate in networks to produce emergent properties that only the system exhibits as the whole.
The first part describes supramolecular gels that undergo gelsol transitions based on different chemical stimuli. Seven different logic gates can be designed based on the same gelator depending on the choice of additives and stimuli.
The second part discusses a synthetic analogue of a signaling cascade realized on the basis of cucurbituril host-guest chemistry. Depending on the inputs given into the system, it reorganizes and different foldamers of a programmed guest chain can be accomplished. Both first parts represent systems that are driven out of equilibrium by the external stimuli and then react by returning into another equilibrium.
The third part finally shows how to use a supramolecular polymer self-assembling from easy-to-synthesize monomers as a truly dissipative supramolecular machine for the directional transport of particles as their cargo over millimeter distances. The direction is defined by a salt gradient and the energy dissipated in the process comes from the crystallization of flexible, bent and partially amorphous ribbons into rigid rods. Overall, this supramolecular machine generates external work from chemical energy. The structural details have been unraveled by electron microscopy, small and wide angle X-ray scattering and electron diffraction experiments.
Speaker information
Prof Christoph A. Schalley, Freie Universität Berlin. The Schalley group works in the field of supramolecular chemistry and aims at generating complex molecular architecture. For example, we have investigated template effects for the synthesis of mechanically interlocked molecules, examined self-assembly and self-sorting phenomena to build supramolecular architecture based on programs that are written into the building blocks and are currently studying rotaxane-based switches at surfaces with the aim to generate macroscopic and concerted switching through the generation of order. The group’s methodological specialty is to investigate the intrinsic properties of supramolecules in the gas phase by mass spectrometry. For this purpose, chemical reactions (e.g. collision-induced decay, infrared multiphoton dissociation, and bimolecular isotope exchange reactions) are carried out in the high vacuum of a mass spectrometer. These gas-phase chemistry experiments reveal a completely new view on the reactivity of supramolecular complexes, as the intramolecular rearrangements become visible, which are superimposed in solution by dynamic exchange processes. Recently, the group is taking more and more materials such as gels and supramolecular polymers into its focus.