Fullerene–ferrocene dyad linked by rigid bilinkage: synthesis, photophysical properties and application as copper ion sensor

A novel fullerene–ferrocene based donor–bridge–acceptor dyad was synthesized and characterized by elemental analysis, FT‐IR, 1H NMR, 13C NMR and FAB‐MS. The dyad with a bilinker comprising of azomethine and ester group was studied for its photo physical properties using absorption spectra and steady‐state fluorescence spectra as a function of dielectric constant of the medium. Fluorescence spectra of the dyad studied with excitation at 449 nm showed a weak emission at 742 nm, which got weaker on increasing the dielectric constant of the medium, indicating efficient electron transfer from ferrocene to fullerene. By designing a bilinked structure between the two redox moieties, we obtained a chelating structure which was found to coordinate copper ion efficiently and hence found application as a metal ion sensor.