16 Circularly Polarized Luminescence …
337
(a)
(b)
200
300
400
500
600
700
-20
-10
0
10
20
CPL / mdeg
Wavelength / nm
(R)-6/7-F/KBr
(R)-6/7-Me/KBr
-150
-75
0
75
150
200
300
400
500
600
700
CD / mdeg
Wavelength / nm
(R)-6/7-Me/KBr
(R)-6/7-F/KBr
Fig. 16.15 Solid-state a CPL and b CD spectra of (R)-6/7-Me/KBr (black lines) and (R)-6/7-F/KBr
(gray lines)
a)
b)
b axis
(R)-6
7-Me
7-Me
d)
b axis
(R)-6
7-Me
(R)-6
c)
A
B
C
7-Me
7-Me
Fig. 16.16 Crystal structures of (R)-6/7-Me. a 2 1 -helical columnar network structure along b axis.
b View along a axis. c Packing structure along b axis. d View along a axis
(R)-6:7-Me = 1:1. This complex has a characteristic 2 1 -helical columnar network
structure along the b axis (Fig. 16.16a, b). This column is mainly composed of the
carboxylate oxygen of the carboxylic acid anions and the ammonium hydrogen of
the protonated amine. (R)-6/7-Me is formed by the self-assembly of these 2 1 -helical
columns, which is driven by the three intercolumnar benzene–benzene edge-to-face
interactions (Fig. 16.16c, d).
In (R)-6/7-F, the stoichiometry is (R)-6:7-F = 1:1 [Fig. 16.17]. Similar to (R)6/7-Me, this complex also has a 2 1 -helical columnar network structure along the a