6
6
0
–6
–12
15
10
5
24
4
0
–4
–8
18
12
6
0
0
6
0
–6
–12
300
400
Absorption
(e / 10 3
M –1
cm –1
)
FL (Normalized
Intensity)
CPL (Normalized
Intensity)
FL (Normalized
Intensity)
CPL (Normalized
Intensity)
FL (Normalized
Intensity)
CPL (Normalized
Intensity)
Absorption
(e / 10 3
M –1
cm –1
)
CD ([q] / 105
degcm 2
dmol –1
)
CD ([q] / 105
degcm 2
dmol –1
)
Absorption
(e / 10 3
M –1
cm –1
)
CD ([q] / 105
degcm 2
dmol –1
)
l abs = 395 nm
l abs = 461 nm
l abs = 552 nm
g abs = 5.6 × 10 –3
g abs = 2.1 × 10 –3
g em = 4.7 × 10 –3
g em = 1.4 × 10 –3
g abs = 0.9 × 10 –3 g em = 0.9 × 10 –3
fr. 1
fr. 2
fr. 1
fr. 2
fr. 1
fr. 2
l em = 488 nm
l em = 580 nm
l em = 685 nm
500
600
700
wavelength / nm
300
400
500
600
700
800
wavelength / nm
300 400
500
600 700 800
900 1000
wavelength / nm
4
2
0
O
O
O
O
O
H
H
NC
CN
O
O
N
N
N
5
6
7
a
b
c
Fig. 4.2 UV-vis absorption (solid) and fluorescence (dashed) spectra (top) and CD and CPL
spectra (bottom) for 5, 6, and 7 in CH 2 Cl 2 . The red and blue bars show the calculated ECD
bands (CAM-B3LYP/6-31G(d)) for the (P)- and (M )-helices, respectively. The transition energies
have been calibrated using a factor of 0.88. Photographs show the emission of 5-7. Reproduced
with permission [15]. Copyright 2017, American Chemical Society
4 Circularly Polarized Luminescence in Helicene and Helicenoid Derivatives
57