200
150
100
50
0
–50
230
280
330
380
430
480
530
580
630
CO
CI
CO
CO
+
OC
Re
N
N
N
N
CO
C
N
+
PF
6
-
OC
Re
N
N
1.0
0.002
0.001
0.000
ΔI
–0.001
–0.002
0.002
0.001
0.000
ΔI
–0.001
–0.002
0.8
0.6
0.4
0.2
0.0
578 668 758
588
498
678 768
Wavelength (nm)
Wavelength (nm)
Irtensity (arb. units)
1.0
0.8
0.6
0.4
0.2
0.0
Irtensity (arb. units)
l / nm
De / M –1 cm –1
(P,C
Re )-70a 1
(P,A
Re )-70a 2
[(M,A
Re )-71a 1
+ (M,C
Re )-71a 2
]
(M)-71a
1,2
CO
CO
Cl
CO
N
N
Re
(M,C
Re )-70a
2
(M,A
Re )-70a
1
(M)-68
i
)
ii
)
(P)-71a 1,2
(M,C
Re )-70a 2
(M)-71a 1,2
(P,A
Re )-70a 2
(M)-71a 1,2
(P )-71a 1,2
–100
–150
–200
Fig. 4.28
Synthesis of enantioenriched rhenium complexes (M,A
Re )-70a
1
, (M,C
Re )-70a
2
, and (M )-71a
1,2
(mixture of two diastereomers). (i) Re(CO)
5 Cl,
toluene, reflux; (ii) AgOTf, EtOH/THF, then 2,6-dimethylphenyl isocyanide, THF, NH
4 PF
6 . X-ray crystallographic structure of 70a
2
. ECD spectra of (P,C
Re )70a
1
, (P,A
Re )-70a
2
and (M )/(P)-71a
1,2
isomers (CH
2 Cl
2 ). Phosphorescence and CPL spectra of (P,C
Re )-70a
1
, (P,A
Re )-70a
2
and (M )/(P)-71a
1,2
isomers
in CH
2 Cl
2 [68]
4 Circularly Polarized Luminescence in Helicene and Helicenoid Derivatives
87