LAUSR

Abstract In this study, the fluorene-group was added to metal complexes, via the easily synthesized β-diketonato ligand. This enables the incorporation of a fluorescent tag into a variety of metal complexes. Three fluorene-containing β-diketones (1–3) were synthesized, characterized and pKa-values determined. The synthesized ligands were complexed with rhodium(I) (4–6). The electrochemistry of compounds 1–6 were studied. The fluorene-group exhibits no electrochemical activity in the solvent window studied. The β-diketonato ligands showed an electrochemically reversible reduction of the ligand backbone at around −2000 mV vs ferrocene as an internal standard. The rhodium(I) complexes exhibited the same ligand reduction at around −2200 mV, with increased chemical reversibility, while the metal center was oxidized at ~300 mV, followed by solvent coordination forming a rhodium(III) species with reduction of this newly formed species at ~1300 mV. The absorbance and fluorescence of all synthesized complexes (1–6) were studied and fluorescence quantum yields were determined and found to be between 0.001 and 0.0001 as measured against anthracene as standard.