Synthesis of new HBC derivatives and investigation of their π

Synthesis of new HBC derivatives and investigation of their --stacking
Mauro Kevin SCHINDLER, Department of Chemistry
In this thesis we have successfully synthesized one of two target HBC derivatives. The
synthetic steps which were performed during this thesis range from relatively simple (as
brominations) to complicated synthetic procedures such as three – fold Sonogashira
couplings. We have tried to simplify the HBC synthesis by introducing a more convergent
synthetic strategy. This strategy allowed to shorten the overall reaction time because several
reaction steps can be done simultaneously. We have also made cryo – SEM measurements
and seen that the synthesized HBC molecule forms spider net – like structures at higher
concentrations and single strains at lower concentrations that shorten in length when the
concentration decreases. UV / VIS measurements have shown that the new HBC derivative
aggregates rapidly in long columns and that the composition of the aggregates changes when
kept in solution for some weeks. Fluorescence measurements revealed small absorption
bands typical for laterally aggregated HBCs. We also discovered that a substance of
unknown composition assembles on the walls of the quartz containers. The HBC derivative
has been totally synthesized and investigated by different direct and indirect methods.
Prof. Dr. Titus A. Jenny