Modular Assembly of Poly(naphthalene diimide) and Ru(II) Dyes for an Efficient Light-Induced Charge Separation in Hierarchically Controlled Polymer Architectures

Hierarchically well-defined multielectron acceptor–photosensitizer (An–P) assemblies were prepared by nitroxide-mediated polymerization of a styrenic naphthalene diimide and subsequent decoration of the chain terminus by a [Ru(dqp)2]2+ photosensitizer (dqp is 2,6-di(quinolin-8-yl)pyridine). In view of a facile modular design, three synthetic linkage procedures were explored aiming at tailored light-initiated energy and electron transfer processes. The polymers were conveniently purified by column chromatography using amino- or diol-functionalized silica gels and were characterized in detail by NMR, MS, and UV−vis-SEC measurements. The electrochemical and absorption data confirmed the preserved individual redox and optical properties of the building blocks. The detailed steady-state emission measurements revealed an efficient quenching of the photosensitizer exceeding 86–96% with respect to reference complexes and the partial sensitization of/by polymer-based excited states. The results demonstrate the general versatility to construct photoredox-active macromolecules from tailored building blocks.