The synthesis of well-defined polymers with pendant perylene bisimide (PBI) groups by a combination of nitroxide-mediated radical polymerization (NMRP) of trimethylsilyl propargyl acrylate followed by copper-catalyzed azide-alkyne cycloaddition (CuAAC, "click" chemistry) is described. The kinetics of NMRP of trimethylsilyl propargyl acrylate polymerization was monitored by 1 H NMR and size exclusion chromatography (SEC). Almost quantitative conversion in the "click" reaction with an azide functionalized PBI derivative was proven by FTIR and 1 H NMR analysis. Thus, semiconductor polymers carrying PBI pendant groups with M n up to 15800 g 3 mol -1 and polydispersity indices as good as 1.16 were obtained by this route. These polymers were compared with poly(perylene bisimide acrylate)s, PPerAcr-(CH 2 ) 11 , and PPerAcr(CH 2 ) 6 , which were synthesized by direct NMRP of PBI acrylates. These samples do not carry any triazol unit and they differ in their spacer length connecting the PBI unit to the main chain. All polymers were comparatively studied by SEC, thermogravimetry, differential scanning calorimetry, polarization microscopy, UV/vis spectroscopy, and photoluminescence measurements. The crystalline structure of the polymers was analyzed by X-ray diffraction. Inductively coupled plasma mass spectrometry analysis confirmed that copper content in the "click" polymer could be reduced down to 126 ppm (w/w).
We investigate in a combined theoretical and experimental study the influence that the specific arrangement, e.g., alternating or random, of donor and acceptor units has on the optical absorption of extended molecules. Because of its important role in low gap polymers we discuss in particular the energetic position of the first electronic transition. We theoretically determine the excitations in extended oligomers with thiophene as the donor and 2,1,3-benzothiadiazole as the acceptor component by using time-dependent density functional theory based on non-empirically tuned range separated hybrid functionals. Corresponding systems are synthesized and theoretical and experimental data are critically compared to each other. We conclude that the influence of the specific arrangement of donor and acceptor monomers on the optical gap is limited and that effects beyond the single molecule level effectively limit the size of the experimentally observed optical gap.
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