Title
Annealing-Induced Circular Dichroism Enhancement in Luminescent Conjugated Polymers with an Intramolecular Stack Structure
Author
Young-Jae Jin, Kyo-Un Seo, Young-Ghil Choi, Masahiro Teraguchi, Toshiki Aoki, Giseop Kwak
Year
2017
Journal
Macromolecules
Abstract
Two poly(diphenylacetylene) derivatives containing identical chiral pinanyl groups on the para- and meta-positions of the side phenyl ring were prepared, and their circular dichroism (CD) and photoluminescence (PL) spectra were compared. The magnitudes of circular polarization (gCD) of the para- and meta-polymers were determined to be 3.1 × 10–3 and 1.4 × 10–3, respectively. The PL quantum yield (PLQY) of the para-polymer was much greater (27.8%) than that of the meta-polymer (2.61%). When the two polymers were annealed at 80 °C in toluene, their CD spectra were remarkably enhanced and reached equilibrium at gCD values of 9.6 × 10–3 and 6.0 × 10–3, respectively. The para-polymer was kinetically more favored for the CD enhancement as known from the fact that the activation energies for the reactions of para- and meta-polymers were determined to be 88 and 187 kJ mol–1, respectively. The PLQYs of both polymers were unaffected by annealing.
Instrument
FP-6500
Keywords
Photoluminescence, Polymers, Quantum yield