Cyclic donor-acceptor circuits: synthesis and fluorescence ion sensory properties of a mixed-heterocyclic dehydroannulene-type cyclophane.
The new dehydroannulene-type cyclophane 5 comprising a conjugated helical framework of thiophene (electron donor) and pyridine (electron acceptor) heterocyclic units has been prepared. Macrocycle 5 was characterized by FAB MS and (1)H and (13)C NMR spectroscopy. Cycle 5 was found to function as a selective precipitation and fluorescence sensor for specific metal ions such as Ag(I) and also exhibited reversible proton-triggered fluorescence quenching behavior. The unique donor-acceptor architecture and spectroscopic properties of 5 suggest that it represents a novel lead class of molecular sensory platforms, with many potential future applications in 21st century materials science.
Baxter
Paul N W
PN
Institut Charles Sadron, UPR 022, 6 Rue Boussingault, F-67083 Strasbourg, France. baxter@ics.u-strasbg.fr