Abstract
When methanol, a nonsolvent, was added to dilute tetrahydrofuran solutions of an optically active polyfluorene derivative, liquid–liquid phase separation occurred, and circular dichroism (CD) was induced at a low temperature. The polymer concentration of the minor separating phase, estimated by light scattering, was very high (∼0.4 g cm−3). The CD induction occurring in that concentrated phase was temperature sensitive. When the phase-separating solution was quenched from 40 to 15 °C, the CD increased according to first-order reaction kinetics, and it was a rather slow process (the rate constant was 2.5 × 10−4 s−1). The intermolecular chiral interaction in the concentrated phase may be responsible for the CD induction or non-racemization of this helical polyfluorene derivative in phase-separating solutions.
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Acknowledgements
This work was partly supported by a Grant-in-Aid for Scientific Research on Priority Area ‘Soft Matter Physics.’ One of the authors (Y Sanada) expresses his special thanks for the global center of excellence program, ‘Global Education and Research Center for Bio-Environmental Chemistry,’ of Osaka University.
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Sanada, Y., Sato, T. Induced circular dichroism of an optically active polyfluorene derivative in phase-separating solutions. Polym J 42, 195–200 (2010). https://doi.org/10.1038/pj.2009.330
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DOI: https://doi.org/10.1038/pj.2009.330
