6 Molecular and Crystal Structures of Polymorphic …
241
Table 6.5 Crystallographic parameters of (a) the five polymorphs of the p-Cl pyrazine dye and (b)
four polymorphs of the o-Br pyrazine dye
(a)
Polymorph
Y
YO
DO
R
RV
Space group
C2/c
P2 1 /n
P2 1 /n
P2 1 /n
P2 1 /c
Z
4
2
2
2
2
a/Å
23.485 (5)
7.680 (2)
14.6554 (5)
9.441 (2)
4.70709 (16)
b/Å
5.974 (1)
18.549 (4)
6.00711 (18) 11.084 (2)
26.1212 (12)
c/Å
22.593 (7)
11.229 (3)
17.9996 (5)
15.303 (3)
12.1528 (5)
α/°
90
90
90
90
90
β/°
102.69 (1)
92.71 (2)
90.1994 (14) 104.380 (9)
93.267 (3)
γ/°
90
90
90
90
90
V /Å 3
3092.3 (1)
1597.9 (6)
1584.2 (8)
1551.1 (5)
1491.82 (11)
d/g/cm 3
1.414
1.368
1.380
1.410
1.466
Refcode
KELFOX01
KELFOX02
KELFOX03
KELFOX
KELFOX04
References
Matsumoto
et al. (2006)
Akune et al.
(2015)
Akune et al.
(2017)
Matsumoto
et al. (2006)
Akune et al.
(2017)
(b)
Polymorph
Y
YO
RO
R
Space group P-1
P-1
P2 1 /n
P-1
Z
1
1
2
1
a/Å
8.55 (4)
7.6207 (9)
12.831 (2)
8.013 (3)
b/Å
10.05 (3)
10.209 (2)
7.241 (1)
9.204 (4)
c/Å
10.93 (7)
11.121 (1)
17.990 (1)
11.328 (5)
α/°
103.5 (2)
79.85 (1)
90
77.00 (2)
β/°
107.3 (3)
84.07 (2)
108.516 (5)
87.33 (2)
γ/°
112.8 (5)
71.51 (1)
90
80.09 (3)
V /Å 3
759 (8)
806.6 (2)
1584.9 (4)
801.8 (6)
d/g/cm 3
1.830
1.721
1.752
1.732
Refcode
KELGEO02
KELGEO03
KELGEO01
KELGEO
References
Matsumoto et al.
(2006)
Matsumoto et al.
(2006)
Matsumoto et al.
(2006)
Matsumoto et al.
(2006)
Figures 6.12 and 6.13 show the 1D column structures and molecular arrangement
of the five forms of the p-Cl derivative and four forms of the o-Br derivative, respectively. The Y and DO forms of the p-Cl derivative form the same packing arrangement
in their 1D columns. These two forms are regarded as 3D isostructures except for a
small difference in the packing of the phenyl rings of the adjacent benzyl groups. In
the Y-form, the phenyl rings stack in a face-to-face manner, while the DO-form adopts
herringbone packing. This confined structural difference is considered an important
factor in their significantly different fluorescence quantum yields (Y: 64%, DO: 14%)
241
Table 6.5 Crystallographic parameters of (a) the five polymorphs of the p-Cl pyrazine dye and (b)
four polymorphs of the o-Br pyrazine dye
(a)
Polymorph
Y
YO
DO
R
RV
Space group
C2/c
P2 1 /n
P2 1 /n
P2 1 /n
P2 1 /c
Z
4
2
2
2
2
a/Å
23.485 (5)
7.680 (2)
14.6554 (5)
9.441 (2)
4.70709 (16)
b/Å
5.974 (1)
18.549 (4)
6.00711 (18) 11.084 (2)
26.1212 (12)
c/Å
22.593 (7)
11.229 (3)
17.9996 (5)
15.303 (3)
12.1528 (5)
α/°
90
90
90
90
90
β/°
102.69 (1)
92.71 (2)
90.1994 (14) 104.380 (9)
93.267 (3)
γ/°
90
90
90
90
90
V /Å 3
3092.3 (1)
1597.9 (6)
1584.2 (8)
1551.1 (5)
1491.82 (11)
d/g/cm 3
1.414
1.368
1.380
1.410
1.466
Refcode
KELFOX01
KELFOX02
KELFOX03
KELFOX
KELFOX04
References
Matsumoto
et al. (2006)
Akune et al.
(2015)
Akune et al.
(2017)
Matsumoto
et al. (2006)
Akune et al.
(2017)
(b)
Polymorph
Y
YO
RO
R
Space group P-1
P-1
P2 1 /n
P-1
Z
1
1
2
1
a/Å
8.55 (4)
7.6207 (9)
12.831 (2)
8.013 (3)
b/Å
10.05 (3)
10.209 (2)
7.241 (1)
9.204 (4)
c/Å
10.93 (7)
11.121 (1)
17.990 (1)
11.328 (5)
α/°
103.5 (2)
79.85 (1)
90
77.00 (2)
β/°
107.3 (3)
84.07 (2)
108.516 (5)
87.33 (2)
γ/°
112.8 (5)
71.51 (1)
90
80.09 (3)
V /Å 3
759 (8)
806.6 (2)
1584.9 (4)
801.8 (6)
d/g/cm 3
1.830
1.721
1.752
1.732
Refcode
KELGEO02
KELGEO03
KELGEO01
KELGEO
References
Matsumoto et al.
(2006)
Matsumoto et al.
(2006)
Matsumoto et al.
(2006)
Matsumoto et al.
(2006)
Figures 6.12 and 6.13 show the 1D column structures and molecular arrangement
of the five forms of the p-Cl derivative and four forms of the o-Br derivative, respectively. The Y and DO forms of the p-Cl derivative form the same packing arrangement
in their 1D columns. These two forms are regarded as 3D isostructures except for a
small difference in the packing of the phenyl rings of the adjacent benzyl groups. In
the Y-form, the phenyl rings stack in a face-to-face manner, while the DO-form adopts
herringbone packing. This confined structural difference is considered an important
factor in their significantly different fluorescence quantum yields (Y: 64%, DO: 14%)