Hydrophilic Poly(naphthalene diimide)‐Based Acceptor–Photosensitizer Dyads: Toward Water‐Processible Modular Photoredox‐Active Architectures

Hydrophilic naphthalene diimide based acceptor polymers are prepared by the incorporation of triethylene glycol or poly(ethylene glycol) side chains in the monomers and subsequent nitroxide-mediated polymerization (NMP). The kinetic investigation of the polymerization reveals a controlled chain growth as well as a narrow molar mass distribution. Due to the utilization of a functional NMP initiator, a single Ru(II) photosensitizer unit is readily attached at the polymers chain terminus by a modular approach to construct water soluble photoredoxactive acceptor-photosensitizer dyads. The analysis of the optical properties by steady-state absorption and emission spectroscopy reveals preserved optical absorption properties of the individual building blocks, and, more importantly, an efficient quenching of the Ru(II) emission assigned to intramolecular charge transfer from the complex to the acceptor polymer. The results demonstrate the versatility of side chain modifications to prepare water-processible photoredox-active architectures under preservation of the modular character known from hydrophobic systems.