128
in 0.6–0.7 μm sized particles, when the RI of the particle was assumed to be 2.0
(e.g. RI = 1.9 at 486 nm for PF8AZO). In contrast, the speed of light in the polymer was halved (3.0 × 10
8
m/s) in a vacuum. Fujiki et al. (2015) also reported that
the l- and r-CP-photons induced chiroptical polarization, depolarization, inversion,
retention and switching to PF8T2 particles. The CPL and PL spectra of (a) h-PF8T2
particles after r- and l-CP-photon irradiation at 546 nm for 60 min and (b) l-PF8T2
particles prepared by the limonene chirality transfer using [(R)- and (S)-limonene]/
CHCl 3 /MeOH (2.0/0.3/0.7 – v/v/v) solvent can be observed in Fig. 6.4.
For h-PF8T2 particles induced by CP-photons, the magnitudes of CPL, defined
as g lum , were −1.1 × 10
–3
at 494 nm, +1.6 × 10
–3
at 530 nm and −3.6 × 10
–3
at 530 nm
for l-CP, while they were −1.1 × 10
–3
at 494 nm, −2.7 × 10
–3
at 530 nm and + 1.8 × 10
–3
at 530 nm for r-CP. For comparison, in the case of limonene-induced l-PF8T2 particles, the magnitudes of CPL were −5.3 × 10
–2
at 509 nm and −4.3 × 10
–2
at 533 nm
for 1R, while they were + 1.9 × 10
–3
at 510 nm and + 1.0 × 10
–2
at 535 nm for (S)limonene. However, the absolute g lum values of these h-PF8T2 particles were considerably weaker by an order of magnitude than those of the limonene-induced
l-PF8T2 particles (Fig. 6.4). This means approx. 6–8% optical purity relative to
4 (a)
3
2
PL
CPL
r-CP-photon
s-CP-photon
0.002
0.000
–0.002
–0.004
–0.006
PL Intensity (l)
CPL Intensity (Dl)
1
0
250 300
400
500
Wavelength / nm
600
700
800
4 (b)
3
2
PL
CPL
R-limonene
s-limonene
0.05
0.00
–0.05
–0.10
–0.15
PL Intensity (l)
CPL Intensity (Dl)
1
0
300
400
500
Wavelength / nm
600
700
800
Fig. 6.4 A comparison of
CPL spectra excited at
400 nm of (a) h-PF8T2
particles induced by r- and
l-CP-photons for 60 min in
CHCl 3 /MeOH (2.1/0.9 –
v/v) and (b) l-PF8T2
particles produced by
limonene chirality transfer
in ((R)- and (S)-limonene)/
CHCl 3 /MeOH
(2.0/0.3/0.7 – v/v/v).
Reproduced with
permission from Fujiki
et al. (2015)
P. Puneet et al.
in 0.6–0.7 μm sized particles, when the RI of the particle was assumed to be 2.0
(e.g. RI = 1.9 at 486 nm for PF8AZO). In contrast, the speed of light in the polymer was halved (3.0 × 10
8
m/s) in a vacuum. Fujiki et al. (2015) also reported that
the l- and r-CP-photons induced chiroptical polarization, depolarization, inversion,
retention and switching to PF8T2 particles. The CPL and PL spectra of (a) h-PF8T2
particles after r- and l-CP-photon irradiation at 546 nm for 60 min and (b) l-PF8T2
particles prepared by the limonene chirality transfer using [(R)- and (S)-limonene]/
CHCl 3 /MeOH (2.0/0.3/0.7 – v/v/v) solvent can be observed in Fig. 6.4.
For h-PF8T2 particles induced by CP-photons, the magnitudes of CPL, defined
as g lum , were −1.1 × 10
–3
at 494 nm, +1.6 × 10
–3
at 530 nm and −3.6 × 10
–3
at 530 nm
for l-CP, while they were −1.1 × 10
–3
at 494 nm, −2.7 × 10
–3
at 530 nm and + 1.8 × 10
–3
at 530 nm for r-CP. For comparison, in the case of limonene-induced l-PF8T2 particles, the magnitudes of CPL were −5.3 × 10
–2
at 509 nm and −4.3 × 10
–2
at 533 nm
for 1R, while they were + 1.9 × 10
–3
at 510 nm and + 1.0 × 10
–2
at 535 nm for (S)limonene. However, the absolute g lum values of these h-PF8T2 particles were considerably weaker by an order of magnitude than those of the limonene-induced
l-PF8T2 particles (Fig. 6.4). This means approx. 6–8% optical purity relative to
4 (a)
3
2
PL
CPL
r-CP-photon
s-CP-photon
0.002
0.000
–0.002
–0.004
–0.006
PL Intensity (l)
CPL Intensity (Dl)
1
0
250 300
400
500
Wavelength / nm
600
700
800
4 (b)
3
2
PL
CPL
R-limonene
s-limonene
0.05
0.00
–0.05
–0.10
–0.15
PL Intensity (l)
CPL Intensity (Dl)
1
0
300
400
500
Wavelength / nm
600
700
800
Fig. 6.4 A comparison of
CPL spectra excited at
400 nm of (a) h-PF8T2
particles induced by r- and
l-CP-photons for 60 min in
CHCl 3 /MeOH (2.1/0.9 –
v/v) and (b) l-PF8T2
particles produced by
limonene chirality transfer
in ((R)- and (S)-limonene)/
CHCl 3 /MeOH
(2.0/0.3/0.7 – v/v/v).
Reproduced with
permission from Fujiki
et al. (2015)
P. Puneet et al.