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Two copolymers, one containing a chiral center and another without any asymmetric site are studied regarding their chiro‐optical properties. The pure polymers do not show any signal of chiro‐optical activity, only a smooth line is observed in the circular dichroism spectra, even for the chiral material. However, blends containing the achiral one as a major component show striking chiro‐optical activity, originating by stable supramolecular structures whose size and shape remain unchanged, regardless of the blend composition. Only the number of such structures (composed by the chiral one), vary with blend composition. The results suggest that working with supramolecular morphology can be an important strategy to attain chiro‐optical active polymers. [ABSTRACT FROM AUTHOR]

Abstract: The emissive properties of terpolymers with fluorene, thiophene and phenylene groups, forming alternating PPV type structures, are discussed in terms of their composition, photo- and electroluminescence properties. The fluorene groups were inserted in each phenylene–vinylene and thiophene–vinylene units, and their concentration did not vary, representing 50% of the molar composition. The ratio of thiophene–vinylene/phenylene–vinylene varied in the range 25, 50 and 75%. Photo- and electroluminescence properties were strongly dependent on the thiophene–vinylene content and were compared with the fluorene–vinylene–thiophene and fluorene–vinylene–phenylene parent copolymers. [Copyright &y& Elsevier]

Abstract: Fluorene and thiophene units are commonly used in polymeric materials for electro-optical applications. Due to differences in reactivity, the final composition of polymers containing these components often differs from that used in their preparation. This contribution describes the synthesis of PPV type terpolymers built by fluorene, phenylene and thiophene units and their quantification by CPMAS NMR. The similarity of the three aromatic co-monomers makes it difficult to separate the analytical responses that would allow quantification of each copolymer unit in the chain. In this sense, we show that the combination of dipolar dephased CPMAS with radiofrequency ramp and proper spectral treatment allows a good estimation and quantification of the copolymer constitution. [Copyright &y& Elsevier]