performed using the pellet holder shown in Fig. 14.14a, which has a scale indicating the
rotation angle. Figure 14.14b shows a KBr pellet installed in the holder.
Figure 14.15 shows spectra of powdered Eu(facam) 3 in a KBr pellet measured
using this pellet holder. The spectra were obtained at rotation angles of 0
, 45
, and
90
. There is no significant change in spectral shape with rotation angle, indicating
that there is little effect of anisotropy.
Since g lum for europium complexes is known to be strongly affected by the type
of solvent used, it was expected that g lum determined using the KBr pellet method
would be different to that for a solution. Figure 14.16 shows CPL spectra of Eu
(facam) 3 in different solvents and in a KBr pellet. g lum values obtained using the KBr
-0.001
0.001
-3
3
0
0.25
CD
]
g
e
d
m
[
g
abs
250
600
Wavelength [nm]
-0.001
0.001
g
lum
-4
4
CPL [mdeg]
0
1
g abs(470 nm)
-0.00002
g lum(507 nm)
-0.0001 -0.0002
300
400
500
Abs
FL [Arb. Unit]
CD/Abs
CPL/FL
Fig. 14.12 CD, CPL, absorption, and fluorescence spectra of enhanced GFP
14 Principles and Applications of Circularly Polarized Luminescence. . .
321