Dyads and Triads Based on Phenothiazine, Bis(terpyridine)ruthenium(II) Complexes, and Fullerene

We report the modular synthesis of donor–photosensitizer–bridge–acceptor (D–P–B–A) triads and D–P dyads for the formation of photoinduced charge‐separated species. The structures are based on a phenothiazine unit (D), a bis(terpyridine) [bis(tpy)] ruthenium(II) complex (P), several phenylene(ethynylene)‐type spacer units (B), and a pyrrolidino[60]fullerene entity (A). The donor–acceptor distance is between 18 and 37 Å and was varied by four different bridging units. The photophysical and electrochemical characterization revealed certain interactions between the active moieties in the ground and the excited state. In particular, a reduced ruthenium‐based emission in the triads indicates the occurrence of a quenching process mediated by the fullerene entity. Strong electrostatic interactions between the ruthenium(II) complex and the pyrrolidino[60]fullerene have been observed for the shortest triad, resulting in the strongest electron‐accepting pyrrolidino[60]fullerene unit in the series.