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Synthesis of pH Dependent Pyrazole, Imidazole, and Isoindolone Dipyrrinone Fluorophores using a Claisen-Schmidt Condensation Approach
Published on: June 10, 2021
Novel molecular building blocks based on the boradiazaindacene chromophore: applications in fluorescent
O Altan Bozdemir1, Onur Büyükcakir, Engin U Akkaya
1Department of Chemistry and UNAM-Institute of Materials Science and Nanotechnology, Bilkent University, 06800 Ankara, Turkey.
Abstract:
We designed and synthesized novel boradiazaindacene (Bodipy) derivatives that are appropriately functionalized for metal-ion-mediated supramolecular polymerization. Thus, ligands for 2-terpyridyl-, 2,6-terpyridyl-, and bipyridyl-functionalized Bodipy dyes were synthesized through Sonogashira couplings. These fluorescent building blocks are responsive to metal ions in a stoichiometry-dependent manner. Octahedral coordinating metal ions such as Zn(II) result in polymerization at a stoichiometry corresponding to two terpyridyl ligands to one Zn(II) ion. However, at increased metal ion concentrations, the dynamic equilibria are re-established in such a way that the monomeric metal complex dominates. The position of equilibria can easily be monitored by (1)H NMR and fluorescence spectroscopies. As expected, although open-shell Fe(II) ions form similar complex structures, these cations quench the fluorescence emission of all four functionalized Bodipy ligands.
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