Defining side chain successions in anthracene-based poly(arylene ethynylene)--poly(phenylene vinylene)s: probing structure-property relationships

By optimizing and adapting the synthesis of double dissymmetric functionalized phenylene building blocks, a library of nine anthracene-containing poly(arylene ethynylene)- alt -poly(phenylene vinylene)s (AnE-PVs) with diverse successions of octyloxy and 2-ethylhexyloxy side chains was realized. Despite the structural resemblance of the regioisomeric comonomers and the polymers, their 1 H NMR spectra were found to feature perceptible side chain configuration-specific patterns. The differentiation of the photophysical characteristics of the polymers induced by the various defined, semi-defined and random side chain sequences has been thoroughly investigated by UV-vis absorption and photoluminescence spectroscopy in solution and in thin film. The gained insights allowed the specification of the notions on the complex structure-property relationships in AnE-PV systems. In particular, the side chain assignment in direct proximity to the anthracene moieties distinctly affects the optical properties. This systematic study presents an illustrative example for the versatile but also intricate capabilities of side chain engineering. A detailed spectroscopic study of nine conjugated polymers with various octyloxy/2-ethylhexyloxy side chain sequences prepared using optimized regio-selective synthetic pathways.