g lum of 1.0 Â 10
À2 in the presence of Cl
–
, whereas almost no CPL was observed without
Cl
–
. meta-Phenylene-bridged dimeric anion-receptor 35 also displayed anionresponsive CPL [53]. 36 formed a helical complex with Cl
–
. Unlike the chiral anionreceptor 35, 36 is an achiral molecule, and thus, the helical complex of 36ÁCl
– is a
racemic mixture that exhibits no CPL without any chiral source. However, once Cl
–
was added as a salt of chiral binaphthylammonium (RR
+
), the helicity of the complex
N
O
O
B
H
N
H
N
O O
Ph
Ph
TBACl
O
O
B
O O
Ph
Ph
N
H
H
H
Cl -
TBA +
35
O
O
B
HN
H
N
F F
Et
Et
Et
Et
O
O B
NH
H
N
F
F
Et
Et
Et
Et
N +
Cl -
36
RRCl
O
O
B
N
N
F
F
Et
Et
Et
Et
O
O
B
N
F
F
Et
Et
N
Et
Et
H
H
H
H
H
H
H
Cl -
N +
Fig. 9.18 Anion-responsive CPL of pyrrole-based anion receptors
9 Circularly Polarized Luminescence of Chirally Arranged Achiral Organic. . .
215