A conjugated thiophene-based rotaxane: synthesis, spectroscopy and modeling
Leszek Zalewski, Michael Wykes, Sergio Brovelli, Massimo Bonini, Thomas Breiner,Marcel Kastler, Florian Dötz, David Beljonne, Harry L. Anderson, Franco Cacialli,Paolo Samorì, Weinheim (2010)
A dithiophene rotaxane 1⊂β-CD and its shape persistent corresponding dumbbell 1 were synthesized and fully characterized. 2D NOESY experiments, supported by molecular dynamics calculations, revealed a very mobile macrocycle (β-CD). Steady-state and timeresolved photoluminescence experiments in solution were employed to elucidate the exited state dynamics for both systems and to explore the effect of cyclodextrin encapsulation. The photoluminescence (PL) spectrum of 1⊂β-CD was found to be blue-shifted with respect to the dumbbell 1 (2.81 eV and 2.78 eV, respectively). Additionally, in contrast to previous observations, neither PL spectra nor the decay kinetics of both threaded and unthreaded systems showed changes upon increasing the concentration or changing the polarity of the solutions, providing evidence for lack of tendency to aggregation of the unthreaded backbone.
Partners : UdS, UMons, UCL, BASF
Place of Publication : Weinheim
Date of Publication : 2010/03/26
Additional Data : CHEMISTRY-A EUROPEAN JOURNAL Volume: 16 Issue: 13 Pages: 3933-3941 Published: 2010