133
poly{[dioctylfluorene]-alt-[bis(thiophenyl)-benzothiazole]} (PF8DBT) via heteroaggregation with PSi-R and PSi-S in a 1/1 ratio as repeating units (Scheme 6.6). The
initial ultra-weak CPL (g em ) and CD (g abs ) amplitudes of the prepared aggregates
were magnified up to 0.019 at 706 nm (induced by PSi-S) and + 0.017 at 695 nm
(induced by PSi-R) after aging prolonged at room temperature for 24 h (Fujiki and
Yoshimoto 2017). These CPL amplitudes were maintained after the selective pho1.0
200
(a)
(b)
100
0
–100
1h
3h
6h
24h
–200
–300
–400
0.01
0.00
–0.01
–0.02
1.0
PL, l = (lL + jR) l2
CPL,
Dl = lL – lR
0.5
0.0
–0.03
–0.04
0.8
0.6
0.4
Absorbance
Ellipticity /mdeg
0.2
0.0
250 300 400 500
Wavelength / nm
600 700 800 900
1.0
200
(c)
100
0
–100
1h
3h
6h
24h
–200
–300
–400
0.8
0.6
0.4
Absorbance
Ellipticity /mdeg
0.2
0.0
250 300 400 500
Wavelength / nm
600 700 800 900
250 300 400 500
Wavelength / nm
600 700 800 900
250300 400 500
Wavelength / nm
600 700 800 900
1h
3h
6h
24h
(d)
0.02
0.01
0.00
–0.01
1.0
PL, l = (lL + IR) j2
CPL,
Dl = lL – jR
0.5
0.0
–0.02
–0.03
1h
3h
6h
24h
6h
24h
Fig. 6.8 Changes in: the (a) CD and UV-Vis-NIR spectra and (b) CPL and PL spectra excited at
400 nm for the PF8DBT-PSi-S hetero-aggregates (1/1 molar ratio). Changes in: (c) the CD and
UV-Vis-NIR spectra and (d) the CPL and PL spectra excited at 400 nm for the PF8DBT-PSi-R
hetero-aggregates (1/1 molar ratio). These aggregates were produced in chloroform/MeOH (2/1
(v/v)). [PF8DBT] = [PSi-S] = [PSi-R] = 2.5 × 10
5  M. Reproduced with permission from Fujiki and
Yoshimoto (2017)
6 Circularly Polarized Luminescent Polymers: Emerging Materials for Photophysical…