Photoinduced Electron Transfer in Clicked Ferrocene-BODIPY-Fullerene Conjugates

Ferrocene-BODIPY (Fc-BDP) conjugates in which one or two ferrocene entities are linked to the beta-positions of the BODIPY core by an ethynyl bridge have been developed. These derivatives were easily and efficiently grafted onto a dual-clickable fullerene platform using CuAAC reactions, leading to a clickable Fc-BDP-C-60 triad and a clickable [Fc](2)-BDP-C-60 tetrad which can be used for further derivatization with complex structures. Due to the extended pi-conjugation and the presence of an intramolecular charge transfer band from Fc to BDP, all these conjugates display a broad absorption in the visible region, which is bathochromically shifted when two Fc are appended to the BDP core. Ultrafast multistep electron transfers leading to charge stabilization were demonstrated in the Fc-BDP-C-60 triad and [Fc](2)-BDP-C-60 tetrad by femtosecond transient absorption studies.