Discotic liquid crystals of transition metal complexes 48:

Article abstract of DOI:10.1142/S1088424613500168

In our previous work, we could successfully synthesize the 1:1 phthalocyanine-fullerene (Pc-C₆₀) dyads, (OFbaC₆₀) PcCu(OCH₃) 2, in very high yields (81 ～ 96%) by using Prato reaction. In this study, we have prepared novel

Full text of DOI:10.1142/S1088424613500168

Journal of Porphyrins and Phthalocyanines
J. Porphyrins Phthalocyanines 2013; 17: 264–282
DOI: 10.1142/S1088424613500168
Published at http://www.worldscinet.com/jpp/
†
Discotic liquid crystals of transition metal complexes 48 :
Synthesis of novel phthalocyanine-fullerene dyads and effect
of a methoxy group on their clearing points
a
a
a
a
b
Masahiro Shimizu , Lisa Tauchi , Takahiro Nakagaki , Aya Ishikawa , Eiji Itoh
a◊
and Kazuchika Ohta*
a
Smart Material Science and Technology, Interdisciplinary Graduate School of Science and Technology, Shinshu
University, 3-15-1 Tokida, Ueda 386-8567, Japan
Department of Electrical and Electronic Engineering, Shinshu University, 4-17-1 Wakasato, Nagano 380-8553,
b
Japan
Received 21 November 2012
Accepted 23 December 2012
ABSTRACT: In our previous work, we could successfully synthesize the 1:1 phthalocyanine-fullerene
(
Pc-C ) dyads, (OFbaC )PcCu(OCH ) 2, in very high yields (81~96%) by using Prato reaction. In this
60 60 3
study, we have prepared novel Pc-C dyads, (OFbaC )PcM (M = Co (a), Ni (b), Cu (c), metal free (d))
6
0
60
3
a–3d without the methoxy group. The target Pc-C dyads 3a–3d could be successfully synthesized in
60
good yields also by Prato reaction. It is surprising for us that removal of a very small methoxy group
from the big (OFbaC )PcCu(OCH ) molecule (2) significantly lowers the cp of (OFbaC )PcCu (3c)
6
0
3
60
by about 70 °C in comparison with that of 2 having the methoxy group. Very interestingly, each of the
novel dyads 3a–3d synthesized here shows perfect homeotropic alignment in the tetragonal columnar
phase (Col ). Moreover, it is noteworthy that 3c and 3d show only one Col mesophase having ordered
tet
tet.o
stacking distance with perfect homeotropic alignment. Such simple phase transition can contribute to
maintain stable performance in wide temperature range, when they will be applied to organic thin film
solar cells.
KEYWORDS: discotic liquid crystal, phthalocyanine, fullerene, phthalocyanine-fullerene dyad,
homeotropic alignment, organic thin film solar cell.
2
004, Kim et al. reported that an organic photovoltaic cell
was fabricated by using liquid crystalline N,N′-diheptyl-
,4,9,10-perylenetetracarboxylicdiimide (PTCDI-C7) as
INTRODUCTION
Liquid crystalline donor–acceptor (D–A) complexes
may display superb performance in organic thin film
solar cells [1–25]. They can greatly reduce their costs
to manufacture the solar cells. Liquid crystalline D–A
systems are broadly classified into three groups: smectic
liquid crystals [1–4], liquid crystalline copolymers
3
the electron acceptor and zinc phthalocyanine (ZnPc) as
the electron donor [1]. The two long chain-substituted
PTCDI-C7 shows, however, a liquid crystalline phase
at very high temperature range (214–403 °C). In 2007,
Hashimoto et al. reported that they synthesized a novel
liquid crystalline oligothiophene(D)-fullerene(A) dyad
to investigate the photovoltaic properties [2]. Moreover,
they revealed that the dyad shows a smectic A phase.
Liquid crystalline donor-acceptor block copolymers
have been also used for photovoltaic applications [5–12].
Morphologies of the vertically oriented mesophase of
D–A separated block copolymers are very favorable
for organic photovoltaics. Furthermore, the covalent
[5–12] and discotic columnar liquid crystals [13–25]. In

SPP full member in good standing
*
Correspondence to: Kazuchika Ohta, email: ko52517@
shinshu-u.ac.jp
†
Part 47: Tenpei Kamei, Takayuki Kato, Eiji Itoh and Kazuchika
Ohta. J. Porphyrins Phthalocyanines 2012; 16: 1261–1275.
Copyright © 2013 World Scientific Publishing Company

DISCOTIC LIQUID CRYSTALS OF TRANSITION METAL COMPLEXES 48
265
bond between the donor and acceptor blocks
is not only desired to improve morphology
control, but also to enhance long term stability
of the device [8]. However, it seems that the
mesophase structure difference between
smectic liquid crystals and discotic columnar
liquid crystals has been not so much concerned
in this field. In comparison with smectic
mesophases, discotic columnar mesophases
are much easier to realize one-dimensional
columnar structure perpendicular to both two
electrodes (= homeotropic alignment) [14, 23,
RO
RO
OR
OR
Previous work
(OMalC )PcCu: 1
60
O
O
R = C12H25
OR
OR
RO
RO
N
N
N
OCH3
O
O
O
O
N Cu N
O C12H24
O
O
N
N
N
O
O
RO
RO
OR
OR
2
5]. Columnar mesophases in homeotropic
alignment are so favorable to obtain higher
photoelectric conversion efficiency which can
be attributable to larger p–p stacking of the
p-conjugated macrocycles [19].
OR
OR
RO
RO
Previous work
(OFbaC60)PcM(OCH3): 2
Discotic liquid crystals are well known to
spontaneously form one-dimensional columnar
structure in their columnar mesophases.
Generally, a discotic columnar liquid crystal
is composed of a plane and hard central core
and several flexible peripheral chains [26].
Especially, triphenylene [27], phthalocyanine
O
O
R = C12H25
a: M = Co
b: M = Ni
c: M = Cu
OR
OR
RO
RO
N
N
N
M
N
OCH3
O C12H24
O
O
N
N
N
N
O
N
(Pc) [28], and porphyrin [28] are often utilized
as a central core part. One-dimensional
columns can be formed by piling up such
disk-like molecules. The column can be a
charge carrier path. In order to achieve efficient
charge transfer, it is favorable to form perfect
homeotropic alignment [14, 19, 23, 25, 29].
On the contrary, it is unfavorable to form both
defects and polydomains in the homeotropic
alignment [29]. Up to date, there have been
some donor-acceptor dyads showing columnar
liquid crystalline mesophases [13–25]. For
example, Bushby et al. reported in 2005 that
a triphenylene derivative connected with
fullerene showed columnar mesomorphism
O
O
RO
RO
OR
OR
OR
OR
This work
OFbaC )PcM: 3
RO
RO
(
60
O
O
a: M = Co
b: M = Ni
c: M = Cu
d: Metal free
R = C12H25
OR
OR
RO
RO
N
N
N
M
N
O
N
N
N
O C12H24
O
O
N
N
[13]. This columnar liquid crystalline
triphenylene-fullerene dyad partially showed
homeotropic alignment, but it has many
defective parts. Recently, columnar liquid
crystalline phthalocyanine-fullerene dyads [14,
O
O
RO
RO
OR
OR
18, 20, 23–25] have been also synthesized.
In 2001, we succeeded in synthesis of
phthalocyanine derivatives showing perfect
homeotropic alignment in large area at high
Fig. 1. Molecular formulae of the previous Pc-C60 dyads (1, 2) and the
present Pc-C60 dyad (3)
temperatures [29]. Furthermore, in 2007 we reported
the first liquid crystalline phthalocyanine-fullerene
dyad, (OMalC )PcCu (1 in Fig. 1), exhibiting perfect
the same time. Accordingly, the yield of the target 1:1
phthalocyanine-fullerene dyad 1 was very low (20%).
Therefore, we changed the synthetic method from Bingel
reaction to Prato reaction [31]. By using Prato reaction
illustrated in Scheme 1, the 1:1 phthalocyanine-fullerene
dyads, (OFbaC )PcM(OCH ) (2 in Fig. 1 and Scheme 1),
60
homeotropic alignment in the hexagonal columnar phase
(
Col ) at high temperatures [14]. For the synthesis of this
h
phthalocyanine-fullerene dyad 1, Bingel reaction [30]
60
3
was adopted to connect phthalocyanine and fullerene.
However, it gave polyads connected with two or three
phthalocyanines per one fullerene, as the by-products at
could be synthesized in very high yields (81~96%) with
negligible amount of undesirable 2:1 phthalocyanine-
fullerene by-product [25]. Thus, Prato reaction was more
Copyright © 2013 World Scientific Publishing Company
J. Porphyrins Phthalocyanines 2013; 17: 265–282

266
M. SHIMIZU ET AL.
OR
OR
RO
RO
OR
R = C12H25
OR
OR
O
O
(
OFbaC60)PcCu(OCH3): 2
OR
NC
NC
OCH3
NC
O
O
RO
RO
N
N
N
Cu
N
OCH3
O
O
OC12H24OH
NC
N
N
(
iii)
N
O
C12H24
O
6
7
N
N
NC
NC
OCH3
OH
OR
OR
O
O
RO
RO
OR
OR
5
(iv)
(vi) 81~96%
(ii)
OR
OR
OR
OR
RO
RO
RO
Br
Br
OCH3
OH
RO
O
O
O
O
(OH)PcCu(OCH3): 8
(OFba)PcCu(OCH3): 9
OR
OR
4
RO
RO
RO
N
N
N
N
N
(v)
N
Cu
N
OCH3
OCH3
O
O
O
O
N
Cu
N
N
N
N
N
(i)
O
C12H24
OH
O
C12H24
O
N
N
N
CHO
RO
OCH3
OH
OR
OR
O
O
O
O
RO
RO
OR
OR
RO
RO
OR
OR
Scheme 1. Synthetic route for the previous Pc-C60 dyad, (OFbaC )PcCu(OCH ): 2, by using Prato reaction. (i) Br /(C H ) O•BF ,
60
3
2
2
5
2
3
CHCl /CH Cl ; (ii) CuCN, DMF; (iii) BrC H OH, K CO /DMF; (iv) DBU/CuCl , n-hexanol; (v) p-formylbenzoic acid, DMAP/
3
2
2
12 24
2
3
2
DCC, CH Cl ; (vi) N-methylglycine, C /toluene. DMAP = 4-dimethylaminopridine. DCC = N,N-dicyclohexylcarbodiimide
2
2
60
favorable to obtain phthalocyanine-fullerene dyads than
Bingel reaction. The Prato 1:1 phthalocyanine-fullerene
dyads 2 also showed perfect homeotropic alignment in the
previously reported method [29]. The phthalocyanine
precursors, (OH)PcM (11) (a: Co, b: Ni, c: Cu, d:
metal free), were synthesized from two different
phthalonitriles 7 and 10 in a molecular ratio of 3:1. The
terminal OH group in 11 was esterified with p-formyl
benzoic acid by Steglich reaction [32] to afford (OFba)
PcM (12). Finally, (OFbaC )PcM (3) was synthesized
from 12 with N-methylglycine and fullerene by Prato
reaction [31]. These procedures are described below
in detail.
tetragonal columnar phase (Col ) at high temperatures [25].
tet
In this work, we have synthesized novel phthalo-
cyanine-fullerene dyads, (OFbaC )PcCu (3 in Fig. 1),
60
by a synthetic route using Prato reaction and another
commercially available starting material, as illustrated in
Scheme 2. Very interestingly, each of the novel dyads 3
shows perfect homeotropic alignment in the tetragonal
6
0
columnar phase (Col ). Moreover, it is surprising for us
4-(12-hydroxydodecyloxy)phthalonitrile
(10).
tet
that removal of a very small methoxy group from the big
A mixture of 4-hydroxyphthalonitrile (0.250 g, 1.73
mmol), 12-bromododecanol (0.600 g, 2.25 mmol),
K CO (0.500 g, 3.62 mmol), and dry DMF (12 mL)
(
OFbaC )PcM(OCH ) molecule (2 in Fig. 1) significantly
60 3
lowers the cp of (OFbaC )PcCu (3c in Fig. 1) by about
60
2
3
70 °C in comparison with that of 2 having the methoxy
was stirred at 160 °C under N for 1 h. The reaction
2
group. We wish to report here the synthesis and very
interesting mesomorphic properties and effect of methoxy
group on the clearing points of the dyads 3.
mixture was extracted with chloroform and washed
with water. The organic layer was dried over Na SO
and evaporated in vacuo. The residue was purified by
2
4
column chromatography (silica gel, chloroform:ethyl
acetate = 4:1, R = 0.85). After removal of solvent,
f
EXPERIMENTAL
0.479 g of white solid was obtained. Yield 84.4%, mp
-
1
6
9.7 °C. IR (KBr): n, cm 3536 (-OH), 2918, 2852
1
(
-CH -), 2234 (-CN), 1598 (Ar). H NMR (4:00 MHz;
2
Synthesis
CDCl ; TMS): d , ppm 7.66 (d, 1H, Ar-H), 7.24 (d, 1H,
3
H
The synthetic route is shown in Scheme 2. The
phthalonitrile derivative, 4,5-bis(3,4-didodecyloxyphe-
noxy)-1,2-dicyanobenzene (7) was prepared by our
Ar-H), 7.15 (d, 1H, Ar-H), 4:01 (t, 2H, -OCH ), 3.62 (t,
2
2H, -OCH ), 2.15 (s, 2H, -CH -), 1.53 (s, 16H, -CH -),
2
2
2
1.48 (s, 2H, -CH -).
2
Copyright © 2013 World Scientific Publishing Company
J. Porphyrins Phthalocyanines 2013; 17: 266–282

DISCOTIC LIQUID CRYSTALS OF TRANSITION METAL COMPLEXES 48
267
RO
RO
OR
OR
NC
NC
O
O
(OFbaC60)PcM: 3
OH
OR
RO
RO
(
i)
OR
N
N
R = C12H25
N
O
O
OR
OR
O
N
N
M
N
OC12H22
NC
NC
N
O
NC
NC
O
N
N
OC12H24OH
OR
O
O
O
a: M = Co
1
0
7
b: M = Ni
RO
RO
OR
OR
c: M = Cu
OR
d: m = Metal free
(ii)
(iv) 76~97%
OR
OR
RO
RO
OR
OR
RO
RO
O
O
O
O
(OH)PcM: 11
(OFba)PcM: 12
OR
OR
OR
RO
RO
RO
N
N
N
N
N
M
N
N
O
O
(iii)
O
O
O
O
N
N
N
M
N
OC12H24OH
OC12H22
O
N
N
N
N
N
H
RO
OR
O
O
O
O
RO
RO
OR
OR
RO
RO
OR
OR
Scheme 2. Synthetic route for novel Pc-C60 dyads, (OFbaC )PcM: 3a–3d, by using Prato reaction. (i) BrC H OH, K CO /DMF;
60
12 24
2
3
(
ii) MCl DBU, n-hexanol; (iii) p-formylbenzoic acid, DMAP/DCC, CH Cl ; (iv) N-methylglycine, C /toluene. DMF = N.N'-
2
,
2
2
6
0
dimethylformamide, DBU = 1,8-diazabicyclo[5,4,0]-7-undecene, DMAA = N,N-dimethylacetamide, DCC = N,N'-dicyclohexyl-
carbodiimide, and DMAP = N,N-dimethyl-4-aminopyridine
2
-(12-hydroxydodecyloxy)-9,10,16,17,23,24-hexa-
kis(3,4-didodecyloxy)phthalocyaninato cobalt(II)
(OH)PcCo:11a).Amixtureof4-(12-hydroxydodecyloxy)
reaction mixture to precipitate the target compound. The
ethanolic layer was removed by filtration. The residue
was extracted with chloroform and washed with water.
The organic layer was dried over Na SO and evaporated
(
phthalonitrile (10) (70.0 mg, 0.213 mmol), 4,5-bis(3,4-
didodecyloxyphenoxy)-1,2-dicyanobenzene (7) (0.600 g,
2
4
in vacuo. The rude product was purified by column
0
.572 mmol), CoCl (33.0 mg, 0.256 mmol), 1-hexanol
chromatography (silica gel, chloroform, R = 0.63) and
2
f
(
11 mL), and DBU (7 drops) was stirred at 150–160 °C
then recrystallized from ethyl acetate to give 0.162 g
of green solid. Yield 23.7%. MS (MALDI-TOF): m/z
3537.22 (calcd. 3536.23).
2-(12-hydroxydodecyloxy)-9,10,16,17,23,24-hexa-
kis(3,4-didodecyloxy)phthalocyaninato copper(II)
((OH)PcCu: 11c). A mixture of 4-(12-hydroxydode-
cyloxy)phthalonitrile (10) (72.0 mg, 0.219 mmol), 4,5-
bis(3,4-didodecyloxyphenoxy)-1,2-dicyanobenzene (7)
under N for 24 h. Ethanol was poured into the reaction
2
mixture to precipitate the target compound. The ethanolic
layer was removed by filtration. The residue was extracted
with chloroform and washed with water. The organic layer
was dried over Na SO and evaporated in vacuo. The crude
product was purified by column chromatography (silica
gel, chloroform, R = 0.63) and then recrystallized from
2
4
f
ethyl acetate to give 0.155 g of green solid. Yield 20.5%.
(0.621 g, 0.591 mmol), CuCl (38.3 mg, 0.285 mmol),
2
MS (MALDI-TOF): m/z 3538.11 (calcd. 3536.23).
1-hexanol (12 mL), and DBU (7 drops) was stirred at
2
-(12-hydroxydodecyloxy)-9,10,16,17,23,24-hexa-
kis(3,4-didodecyloxy)phthalocyaninato nickel(II)
(OH)PcNi: 11b). A mixture of 4-(12-hydroxydode-
150–160 °C under N for 24 h. Ethanol was poured into
2
the reaction mixture to precipitate the target compound.
The ethanolic layer was removed by filtration. The
residue was extracted with chloroform and washed with
water. The organic layer was dried over Na SO and
(
cyloxy)phthalonitrile (10) (70.0 mg, 0.213 mmol), 4,5-
bis(3,4-didodecyloxyphenoxy)-1,2-dicyanobenzene (7)
2
4
(
0.600 g, 0.572 mmol), NiCl (36.0 g, 0.278 mmol),
evaporated in vacuo. The crude product was purified
2
1
1
-hexanol (11 mL), DBU (7 drops) was stirred at 150–
by column chromatography (silica gel, chloroform, R =
0.55) and then recrystallized from ethyl acetate to give
f
60 °C under N for 17 h. Ethanol was poured into the
2
Copyright © 2013 World Scientific Publishing Company
J. Porphyrins Phthalocyanines 2013; 17: 267–282

268
M. SHIMIZU ET AL.
0
.229 g of green solid. Yield 29.5%. MS (MALDI-TOF):
Metal free benzoic derivative ((OFba)PcH : 12d).
2
m/z 354:0.54 (calcd. 354:0.85).
-(12-hydroxydodecyloxy)-9,10,16,17,23,24-he-
xakis(3,4-didodecyloxy)phthalocyanine ((OH)PcH2:
1d). mixture of 4-(12-hydroxydodecyloxy)
phthalonitrile (10) (70.0 mg, 0.213 mmol), 4,5-bis(3,4-
didodecyloxyphenoxy)-1,2-dicyanobenzene (7) (0.600 g,
A mixture of (OH)PcH (11d) (0.120 g, 0.0349 mmol),
2
2
p-formyl benzoic acid (7.76 mg, 0.0517 mmol), N,N′-
dicyclohexylcarbodiimide (10.7 mg, 0.0517 mmol),
N,N-dimethyl-4-aminopyridine (25.3 mg, 0.207 mmol),
and dry CH Cl (11 mL) was stirred at rt under N for 24
1
A
2
2
2
h. The reaction mixture was extracted with chloroform
and washed with water. The organic layer was dried over
Na SO and evaporated in vacuo. The residue was purified
0
.572 mmol), 1-hexanol (11 mL), DBU (7 drops) was
stirred at 150–160 °C under N for 24 h. Ethanol was
2
2
4
poured into the reaction mixture to precipitate the target
compound. The ethanolic layer was removed by filtration.
The residue was extracted with chloroform and washed
with water. The organic layer was dried over Na SO
by column chromatography (silica gel, chloroform:n-
hexane = 10:1, R = 0.93) and then recrystallized from
f
ethyl acetate to give 0.0844 g of green solid..Yield 66.5%.
MS (MALDI-TOF): m/z 3614.27 (calcd. 3610.43).
Cobalt fullerene derivative ((OFbaC )PcCo: 3a). A
2
4
and evaporated in vacuo. The crude product was purified
6
0
by column chromatography (silica gel, chloroform:n-
mixture of (OFba)PcCo (12a) (50.0 mg, 0.0136 mmol),
hexane = 3:1, R = 0.50) and then recrystallized from
C fullerene (19.6 mg, 0.0272 mmol), N-methylglycine
f
60
ethyl acetate to give 0.188 g of green solid. Yield 27.9%.
MS (MALDI-TOF): m/z 3482.63 (calcd. 3479.32).
Cobalt benzoic derivative ((OFba)PcCo: 12a). A
mixture of (OH)PcCo (11a) (0.120 g, 0.0339 mmol),
p-formyl benzoic acid (11.5 mg, 0.0763 mmol), N,N′-
dicyclohexylcarbodiimide (70.0 mg, 0.339 mmol), N,N-
dimethyl-4-aminopyridine (12.4 mg, 0.102 mmol), and
dry CH Cl (20 mL) was stirred at rt under N for 30 h.
(2.91 mg 0.0326 mmol), and dry toluene (80 mL)
was stirred at 120 °C under N for 24 h. The reaction
2
mixture was extracted with chloroform and washed with
water. The organic layer was dried over Na SO and
2
4
evaporated in vacuo. Unreacted fullerene was removed
by chromatography (silica gel, toluene, R = 1.0), and the
f
residue in silica gel was flushed out with THF. The crude
product was recrystallized from ethyl acetate at rt and
THF at -20 °C, respectively. After removal of solvent,
47.9 mg of green solid was obtained. Yield 79.8%. MS
(MALDI-TOF): m/z 4416.57 (calcd. 4415.07).
2
2
2
The reaction mixture was extracted with chloroform and
washed with water. The organic layer was dried over
Na SO and evaporated in vacuo. The residue was purified
2
4
by column chromatography (silica gel, chloroform, R =
Nickel fullerene derivative ((OFbaC )PcNi: 3b). A
f
60
0
0
.90) and then recrystallized from ethyl acetate to give
.108 g of green solid. Yield 87.3%. MS (MALDI-TOF):
mixture of (OFba)PcNi (12b) (60.0 mg, 0.0164 mmol),
C fullerene (23.6 mg, 0.0327 mmol), N-methylglycine
6
0
m/z 3671.58 (calcd. 3667.34).
(2.92 mg 0.0328 mmol), and dry toluene (90 mL)
Nickel benzoic derivative ((OFba)PcNi: 12b). A
mixture of (OH)PcNi (11b) (0.120 g, 0.0339 mmol),
p-formyl benzoic acid (11.2 mg, 0.0747 mmol), N,N′-
dicyclohexylcarbodiimide (70.0 mg, 0.339 mmol), N,N-
dimethyl-4-aminopyridine (12.4 mg, 0.102 mmol), and
dry CH Cl (20 mL) was stirred at rt under N for 24 h.
was stirred at 120 °C under N for 14 h. The reaction
2
mixture was extracted with chloroform and washed with
water. The organic layer was dried over Na SO and
2
4
evaporated in vacuo. Unreacted fullerene was removed
by chromatography (silica gel, toluene, R = 1.0), and the
f
residue in silica gel was flushed out with THF. The crude
product was recrystallized from ethyl acetate at rt and
THF at -20 °C, respectively. After removal of solvent,
70.1 mg of green solid was obtained. Yield 96.8%. MS
(MALDI-TOF): m/z 4424.4 (calcd. 4415.07).
2
2
2
The reaction mixture was extracted with chloroform and
washed with water. The organic layer was dried over
Na SO and evaporated in vacuo. The residue was purified
2
4
by column chromatography (silica gel, chloroform, R =
f
0
0
.89) and then recrystallized from ethyl acetate to give
.122 g of green solid. Yield 98.7%. MS (MALDI-TOF):
Copper fullerene derivative ((OFbaC )PcCu: 3c).
6
0
A mixture of (OFba)PcCu (12c) (60.0 mg, 0.0163 mmol),
C fullerene (23.4 mg, 0.0325 mmol), N-methylglycine
m/z 3670.47 (calcd. 3667.34).
6
0
Copper benzoic derivative ((OFba)PcCu: 12c). A
mixture of (OH)PcCu (11c) (0.150 g, 0.0424 mmol),
p-formyl benzoic acid (9.53 mg, 0.0635 mmol), N,N′-
dicyclohexylcarbodiimide (13.1 mg, 0.0635 mmol), N,N-
dimethyl-4-aminopyridine (31.0 mg, 0.254 mmol), and
dry CH Cl (15 mL) was stirred at rt under N for 24 h.
(3.47 mg 0.0389 mmol), and dry toluene (60 mL)
was stirred at 120 °C under N for 14 h. The reaction
2
mixture was extracted with chloroform and washed with
water. The organic layer was dried over Na SO and
2
4
evaporated in vacuo. Unreacted fullerene was removed
by chromatography (silica gel, toluene, R = 1.0), and the
2
2
2
f
The reaction mixture was extracted with chloroform and
washed with water. The organic layer was dried over
Na SO and evaporated in vacuo. The residue was purified
residue in silica gel was flushed out with THF. The crude
product was recrystallized from ethyl acetate at rt and
THF at -20 °C, respectively. After removal of solvent,
61.3 mg of green solid was obtained. Yield 85.1%. MS
(MALDI-TOF): m/z 4424.18 (calcd. 4419.69).
2
4
by column chromatography (silica gel, chloroform, R =
f
0
.90) and then recrystallized from ethyl acetate to 0.102
g of give green solid. Yield 65.0%. MS (MALDI-TOF):
Metalfreefullerenederivative((OFbaC )PcH :3d).
60
2
m/z 3676.71 (calcd. 3671.96).
A mixture of (OFba)PcH (12d) (47.0 mg, 0.0130 mmol),
2
Copyright © 2013 World Scientific Publishing Company
J. Porphyrins Phthalocyanines 2013; 17: 268–282

DISCOTIC LIQUID CRYSTALS OF TRANSITION METAL COMPLEXES 48
269
C60 fullerene (18.7 mg, 0.0259 mmol), N-methylglycine
2.77 mg 0.0311 mmol), and dry toluene (65 mL)
behavior of the present compounds was observed with
polarizing optical microscope (Nikon ECLIPSE E600
POL) equipped with a Mettler FP82HT hot stage and
a Mettler FP-90 Central Processor, and differential
scanning calorimeter (Perkin-Elmer Diamond DSC.) The
mesophases were identified by using a wide angle X-ray
diffractometer (Rigaku Rad) equipped with Cu-Ka
radiation and a handmade hot stage equipped with a
temperature controller [33].
(
was stirred at 120 °C under N for 14 h. The reaction
2
mixture was extracted with chloroform and washed with
water. The organic layer was dried over Na SO and
2
4
evaporated in vacuo. Unreacted fullerene was removed
by chromatography (silica gel, toluene, R = 1.0), and
f
the residue in silica gel was flushed out with THF. The
crude product was recrystallized from ethyl acetate at rt
and THF at -20 °C, respectively. After removal of solvent,
4
3.0 mg of green solid was obtained. Yield 75.8%. MS
RESULTS AND DISCUSSION
(MALDI-TOF): m/z 4366.84 (calcd. 4358.16).
Measurements
Synthesis of the novel Pc compounds: 11a–11d,
1
2a–12d, and 3a–3d
1
The H NMR measurements were carried out by
1
using H NMR (BRUKER Ultrashield 400 MHz). The
Table 1 summarizes MALDI-TOF mass spectra
elemental analyses were performed by using a Yanaco
CHN CORDER MT-3. The MALDI-TOF mass spectral
measurements were carried out by using a PerSeptive
Biosystems Voyager DE-Pro spectrometer (matrix:
dithranol). Infrared absorption spectra were recorded
by using a Nicolet NEXUS670 FT-IR. Electronic
absorption (UV-vis) spectra were recorded by using a
HITACHI U-4100 spectrophotometer. Phase transition
data, elemental analysis results, and yields of 11a-11d,
12a-12d, and 3a–3d. The 3:1 precursors, (OH)PcM
(11), could be prepared in 20–30% of yields. These
low yields resulted from the inevitable by-product of
the 4:0 phthalocyanine composed of only 4,5-bis(3,4-
didodecyloxyphenoxy)-1,2-dicyanobenzene units. On the
other hand, the precursors, (OFba)PcM (12), could be
prepared in good yields by Steglich esterification [32]. The
Table 1. MALDI-TOF mass spectral data and elemental analysis data of (OH)PcM: 11a–11d, (OFba)PcM: 12a–12d, and (OFbaC )
60
PcM: 3a–3d.
Compound
Mol. formula
Mol. wt)
Mass observed
Elemental analysis: Found(Calcd.)(%)
Yield
(%)
(
N
C
H
C224H352N O Co
8
20
1
1
1
1
1
1
1
1
3
3
3
3
1a: (OH)PcCo
1b: (OH)PcNi
1c: (OH)PcCu
1d: (OH)PcH2
2a: (OFba)PcCo
2b: (OFba)PcNi
2c: (OFba)PcCu
2d: (OFba)PcH2
a: (OFbaC )PcCo
3538.11
3537.22
3.10 (3.17)
76.4 (76.08) 10.26 (10.03) 20.5
75.94 (76.09) 10.15 (10.03) 23.7
76.14 (75.98) 10.21 (10.02) 29.5
76.96 (77.33) 10.61 (10.26) 27.9
(3536.23)
C224H352N O Ni
8
20
3.17 (3.17)
3.20 (3.16)
3.13 (3.22)
2.96 (3.06)
3.09 (3.06)
3.01 (3.05)
3.09 (3.10)
—
(3535.99)
C224H352N O Cu
8
20
3540.54
(3540.85)
C224H354N O
8
20
3482.63
(3479.32)
C232H355N O Co
8
22
3671.58
76.15 (75.98) 10.11 (9.76)
75.72 (75.99) 10.09 (9.76)
76.24 (75.89) 10.14 (9.74)
77.23 (77.18) 10.31 (9.97)
87.3
98.7
65.0
66.5
79.8
96.8
85.1
75.8
(3667.34)
C232H355N O Ni
8
22
3670.47
(3667.10)
C232H355N O Cu
8
22
3676.71
(3671.96)
C232H357N O
8
22
3614.27
(3610.43)
C294H360N O Co
9
21
4416.57, 3695.94
4424.47, 3700.34
4424.18, 3705.23
4366.84, 3643.64
—
—
—
—
—
—
—
—
60
(4415.07)
C294H360N O Ni
9
21
b: (OFbaC )PcNi
—
60
(4414.83)
C294H360N O Cu
9
21
c: (OFbaC )PcCu
—
60
(4419.69)
C294H362N O
9
21
d: (OFbaC )PcH
2
—
60
(4358.16)
Copyright © 2013 World Scientific Publishing Company
J. Porphyrins Phthalocyanines 2013; 17: 269–282

270
M. SHIMIZU ET AL.
corresponding dyads, (OFbaC )PcM (3), were synthesized
phthalocyanine discotic liquid crystals tend to aggregate
60
-6
by Prato reaction [31]. All the products gave satisfactory
molecular weights by MALDI-TOF mass spectra. The
elemental analysis data of the precursors 11 and 12 are in
agreement with the theoretical values. However, the dyads
even in a very dilute chloroform solution like as 10 M.
1
We could not measure H NMR spectra for such a dilute
solution. So, we need to increase the concentration to ca.
-3
10 M for the NMR measurements. However, very strong
aggregation took place in such a concentrated solution, and
it always gave the very broad meaningless NMR spectra.
3a–3d did not completely burn out at the measurement
temperature (850 °C). Therefore, these elemental analysis
data are not listed up in Table 1. Electronic absorption
Accordingly, we used the other solvents, DMSO-d and/or
6
(UV-vis) spectra were recorded in order to confirm the
THF-d , for the Pc-C dyads, 3b, 3d, but the dyads were
8
60
existence of the phthalocyanine and fullerene parts.
In Table 2 are listed electronic spectral data of all the
compounds, 11, 12 and 3. The UV-vis spectra are illustrated
in Fig. 2. As can be seen from these table and figure, each
of the compounds 11, 12 and 3, shows Q-band (600–700
nm) and Soret band (300–400 nm) characteristic to the
phthalocyanine macrocycle. As can be seen from Fig. 2d,
each of the Pc compounds 3d, 11d and 12d gave split
Q-band characteristic to a metal free phthalocyanine. Each
of the dyads 3a–3d gave an additional absorption peak at
ca. 250 nm attributed to fullerene moiety, whereas the other
phthalocyanine precursors, 11a–11d and 12a–12d, did not
give this peak. This fact clearly supports that fullerene is
connected with phthalocyanine in the dyads 3a–3d. Thus,
we confirmed that all the target Pc-fullerene dyads 3 could
be successfully synthesized.
totally insoluble in DMSO and less soluble in THF than
chloroform. Even for the saturated solution in hot THF-
1
d , it gave a very broad meaningless H NMR spectrum
8
due to the strong aggregation. Thus, all our trials were in
vain for the NMR measurements. However, as mentioned
above we confirmed from MALDI-TOF mass spectra and
the UV-vis spectra that all the target Pc-fullerene dyads 3
could be successfully synthesized.
Unusual phase transition behavior of 11 and 12
The phase transition behavior of the PcM precursors
(11 and 12) and the PcM-C60 dyads (3) is summarized
in Table 3. Their X-ray data of 11, 12 and 3 are listed
in Table 4. The phase transition behavior was revealed
by polarization microscopy (POM), differential scanning
calorimetry (DSC), temperature-dependent X-ray
diffraction measurements and temperature-dependent
electronic spectrometry.
1
Although we tried to measure H NMR spectra of
the diamagnetic Pc derivatives, 11b, 11d ; 12b, 12d and
3b, 3d, all our attempts were in vain. As is well-known,
Table 2. Electronic spectral data of (OH)PcM: 11 (a = Co, b = Ni, c = Cu, and d = H ), (OFba)PcM: 12 (a = Co, b = Ni, c = Cu, and
2
d = H ), and (OFbaC )PcM: 3 (a = Co, b = Ni, c = Cu, and d = H ).
2
60
2
a
Compound
Concentration
lmax (nm) (loge)
-5
(X10 mol/l)
C60 peak
Soret-band
Q-band
(
OH)PcCo: 11a
OH)PcNi: 11b
1.2
1.0
327.7 (4.9) 608.8 (4.6)
643.4 (sh)
646.2 (sh)
677.1 (5.2)
675.6 (5.3)
(
289.4 (5.0) 306.6 330.3 (sh)
5.0)
628.4 (4.6)
(
(
OH)PcCu: 11c
1.8
290.8 (4.9)
291.1 (4.8)
340.2 (5.0) 615.4 (4.7)
342.9 (4.9) 608.3 (4.4)
651.8 (4.6)
686.7 (5.3)
(OH)PcH : 11d
0.98
644.8 669.8 704.3 (5.1)
4.6) (5.1)
2
(
(
OFba)PcCo: 12a
OFba)PcNi: 12b
1.0
1.0
327.1 (5.3) 608.6 (4.6)
642.7 (sh)
647.6 (sh)
675.9 (5.2)
675.9 (5.3)
(
288.6 (5.0) 305.3 330.2 (sh)
5.0)
608.6 (4.6)
(
(
OFba)PcCu: 12c
1.6
1.2
291.3 (4.9)
291.5 (4.8)
341.3 (4.9) 615.0 (4.6)
345.3 (4.9) 607.4 (4.9)
652.5 (sh)
685.0 (5.3)
(OFba)PcH : 12d
643.9 670.0 702.8 (5.1)
0.51) (5.1)
2
(
(
(
(
OFbaC )PcCo: 3a
0.63
0.54
0.52
0.53
245.0
5.2)
292.8
(5.1)
609.2 (4.5)
642.9 (sh)
647.8 (sh)
652.2 (sh)
677.2 (5.2)
676.1 (5.1)
684.9 (5.2)
60
(
OFbaC )PcNi: 3b
248.0
5.1)
283.3
(5.0)
309.2 328.2 (sh)
(5.0)
610.9 (4.5)
60
(
OFbaC )PcCu: 3c
255.6
5.2)
292.7
(sh)
340.3 (5.0) 618.1 (4.7)
338.8 (4.9) 610.9 (4.5)
60
(
(OFbaC )PcH : 3d
254.5
5.1)
288.6 (5.0)
641.4 669.7 704.3 (5.1)
(4.6) (5.0)
60
2
(
a
:
in chloroform.
Copyright © 2013 World Scientific Publishing Company
J. Porphyrins Phthalocyanines 2013; 17: 270–282

DISCOTIC LIQUID CRYSTALS OF TRANSITION METAL COMPLEXES 48
271
Fig. 2. UV-vis spectra in CH Cl at room temperature: (a) PcCo (11a, 12a, and 3a), (b) PcNi (11b, 12b, and 3b), (c) PcCu (11c, 12c,
3
and 3c), and (d) PcH (11d, 12d, and 3d)
2
As can be seen from Table 3, each of the (OH)PcM
derivatives (11a–11d) shows very interesting phase
transition sequence, e.g. K(R) à Col (R) à Col (F) à
[34] for the excited energy levels as illustrated in Fig. 3.
As can be seen from Fig. 3d, when roof-top-shaped
dimers are formed, the excited energy level is split into
two levels. Hence, the Q-band of phthalocyanine should
be split into two peaks only in the roof-top-shaped dimer.
Representative UV-vis spectra of the thin films of 11b,
tet
h
Col (F) à I.L. for (OH)PcNi (11b) on heating stage.
tet
(R) and (F) mean roof-top-shaped dimer stacking and
face-to-face stacking, respectively. On cooling from I.L.,
it gave Cub(Pn3m). On further cooling the Cub phase
relaxed into Col (F) and then it transformed into Col (F).
12b, and 3b are shown in Fig. 4. The Col (R) mesophase
tet
of 11b at 80 °C gave a shoulder at ca. 750 nm. The peak
at ca. 680 nm and the shoulder at ca. 750 nm correspond
to two split Q-bands. However, the shoulder at ca. 750
nm disappeared with heating and did not appear again
tet
h
The Col (F) mesophase was supercooled till rt. Thus, the
h
(OH)PcNi (11b) derivative gave a very peculiar phase
transition like as Col (R) à Col (F) à Col (F). As can
tet
h
tet
be seen from Table 3, the (OFba)PcNi (12b) derivative
also showed unusual phase transitions like as K(R) à
Col (R) à Col (F) à I.L. on heating stage, and I.L. à
on cooling. On the other hand, the Col (R) mesophase
of 12b at 80 °C gave a much clearer shoulder at ca. 750
nm. Although the shoulder at ca. 750 nm disappeared
tet
tet
tet
Cub(Pn3m) à M à Col (R) à Col (R) à K(R) on
on further heating, it appeared again for the Col (R)
x
h
tet
h
cooling stage. These unusual phase transition sequences
of 11 and 12 are resulted from formation, deformation,
and reformation of roof-top-shaped dimers.
mesophase on cooling stage.
These spectral changes agree with the stacking
distances in the XRD data listed in Table 4. As can be
seen from this table, the Col (R) mesophase of 11b at
tet
8
0 °C, for example, gave a sharp peak at 4.87 Å (h ) and
1
Formation, deformation and reformation of the roof-
top-shaped dimers of 11 and 12
a broad peak at ca. 9.4 Å (h : approximately two times
2
of 4.87 Å). Taking into account these two stacking
distances at 4.87 Å and two times of the stacking
distance at ca. 9.2 Å, it is consistent with formation
UV-vis spectra of the thin film certified the roof-top-
shaped dimer formation, which is based on Kasha’s rule
Copyright © 2013 World Scientific Publishing Company
J. Porphyrins Phthalocyanines 2013; 17: 271–282

272
M. SHIMIZU ET AL.
Table 3. Phase transition temperatures and enthalpy changes of all compounds
T/ o
C
[
∆H/ kJ mol -1
]
Compound
Phasea)
Phase
very broad
r.t.-80
99.8[19.6]
128.1[29.4]
110.3[16.3]
174.2 [2.18]
(
(
OH)PcCo: 11a K(R)
Coltet(R)
Coltet(R)
Col
h
(F)
(F)
Coltet(F)
I.L.
Cub
1
69.7
ca.139
(
Pn3m) [0.926]
very broad
r.t.-80
92.0[23.0]
172.3 [2.20]
OH)PcNi: 11b
K(R)
Col
h
Coltet(F)
I.L.
Broad
Cub
Pn3m)
167.9 [1.70]
172.3
[2.20]
1
50-120
(
9
4.0 [27.8]
135.2
#
37.5#
1
(
OH)PcCu: 11c K(R)
Col (F)
M
x
Coltet(F)
I.L.
h
Cub
Pn3m)
ca.138
ca.138
ca.160 *
(
4
7.3 [41.2]
74.0[38.6]
(
OH)PcH : 11d K(R)
Coltet(R)
Coltet(R)
Coltet(F)
I.L.
2
Cub
Pn3m)
ca.98
ca.136
(
5
1.0[94.2]
114.8[35.1]
121.2[10.2]
1
68.1 [3.30]
(
(
OFba)PcCo: 12a K(R)
OFba)PcNi: 12b K(R)
M (R)
x
Coltet(F)
I.L.
Cub
Pn3m) [1.99]
162.6
Broad
1
40-125
(
3
3.9[76.5]
97.5[46.7]
1
66.7[2.42]
Coltet(R)
Coltet(F)
I.L.
8
6.4
162.5
[1.20]
Cub
Col (R)
Mx
[24.7]
h
9
8.2[12.4]
08.7[5.75]
101.2[4.95] (Pn3m)
1
1
03.9[26.0]
159.5[1.03]
4
6.0[90.0]
(
OFba)PcCu: 12c K(R)
Coltet(R)1
Coltet(R)
Coltet(R)2
Coltet(F)
I.L.
Cub
Pn3m)
ca.160
(
4
8.4 [113.9]
96.9 [25.2]
1.8
133.4[1.08]
(
OFba)PcH : 12d K(R)
Coltet(F)
I.L.
2
9
Cub
9
6.3
(
Pn3m) [2.00]
4
3.4 [36.9]
7.2[54.8]
71.0[10.3]
76.6[9.71]
Coltet.2¶
96.1[8.00]
92.4[12.2]
Coltet.1¶
Coltet.o
I.L.(decomp.)+
(
OFbaC60)PcCo: 3a
K
3
I.L.(decomp.)+
(
OFbaC60)PcNi: 3b
K
Coltet.d
4
4.0 [70.5]
7.0[67.4]
88.3[27.2]
I.L.(decomp.)+
I.L.((decomp.)+
(
OFbaC60)PcCu: 3c
K
K
Coltet.o
Coltet.o
4
89.5[41.4]
(
OFbaC60)PcH : 3d
2
(
a) Phase nomenclature: K = crystal, Col = hexagonal columnar mesophase, Coltet.0 = tetragonal ordered columnar
h
mesophase, Coltet.d = tetragonal disordered columnar mesophase, M = unidentified mesophase, Cub = cubic meso-
x
phase, I.L. = isotropic liquid, (R) = roof-top-shaped dimer stacking and (F) = face-to-face stacking. * = the DSC peak
was too small to estimate the enthalpy change, + = gradual decomposition after clearing, # = two peaks were too
close to determine the enthalpy changes,  = mesophase shawing homeotropic alignment, and ¶ = This mesophase
gave only one XRD peak in the low angle region. Although the mesophase was impossible to be established from
the one peak, it was tentatively identified as a Coltet mesophase.
of the roof-top-shaped dimers in the columns. When
Col (R) mesophase changed into face-to-face stacking
tet
it was further heated up into the Col (F) mesophase
in the Col (F) mesophase at the phase transition from
h
h
at 105 °C, the peak at 4.87 Å disappeared and a
broad peak appeared at ca. 3.5 Å instead, as listed in
this table. Stacking distance of ca. 3.5 Å is a typical
stacking distance of phthalocyanine disks stacked face-
to-face. Therefore, the roof-top-shaped dimers in the
Col (R) to Col (F) at 92.0 °C. As can be seen from
tet
h
Table 3, the Col (F) mesophase changed into another
h
tetragonal mesophase, Col (F), at 110.3 °C, which
tet
cleared into isotropic liquid (I.L.) at 172.3 °C. It is
very interesting that a Cub mesophase, Cub(Pn3m),
Copyright © 2013 World Scientific Publishing Company
J. Porphyrins Phthalocyanines 2013; 17: 272–282

DISCOTIC LIQUID CRYSTALS OF TRANSITION METAL COMPLEXES 48
273
Table 4 X-ray data of (OH)PcM (11a–11d), (OFba)PcM (12a–12d) and (OFbaC )PcM (3a–3d).
60
Spacing/A
Miller indices
Compound
Lattice constants/A
(hkl)
Observed
33.2
3.0
Calculated
(OH)PcCo:11a
Col (R) at 85°C
33.2
23.5
14.8
—
(1 0 0)
(1 1 0)
(2 1 0)
h2
tet
2
a = 33.2
h2 = ca. 9.3
14.6
ca. 9.3
4.89
h1 = 4.89
—
h1
Z = 0.92 for ρ = 1.0
ca. 4.5
33.7
—
#
Col (F) at 115°C
33.7
19.5
12.7
—
(1 0 0)
(1 1 0)
(2 1 0)
#
h
a = 38.9
19.9
13.1
ca. 4.6
30.2
Col (F) at 160°C
30.5
21.5
—
(1 0 0)
(1 1 0)
#
tot
a = 30.5
21.5
ca. 4.6
Cub(Pn3m) at 163°C on
cooling
39.4
39.4
(3 2 1)
a = 147
35.0
35.0
33.4
30.2
20.5
—
(3 3 0)
33.4
30.2
20.5
(3 3 1)
(4 2 2)
(6 4 0)
ca. 13.2
ca. 9.4
ca. 4.7
ca. 3.6
33.7
#
—
#
—
#
h
—
(OH)PcNi: 11b
Col (R) at 80°C
33.7
23.8
—
(1 0 0)
(1 1 0)
h2
tet
a = 33.7
h2 = ca. 9.4
h1 = 4.87
23.0
ca. 9.4
4.87
—
h1
Z = 1 for ρ = 1.2
ca. 4.4
34.0
—
#
Col (F) at 105°C
34.0
19.6
12.9
—
(1 0 0)
(1 1 0)
(2 1 0)
#
h
20.3
a = 39.3
h = ca. 3.5
13.3
ca. 9.0
ca. 4.5
ca. 3.5
31.5
Z = 1 for ρ = 1.2
—
#
—
h
Col (F) at 130°C
31.2
(1 0 0)
tet
a = 31.2
22.1
ca. 4.6
22.1
—
(1 1 0)
#
#
= Halo of the molten alkoxy chains. h = stacking distance between the monomers. h = stacking distance
1 2
between the dimers. ¶ = This mesophase gave only one XRD peak in the low angle region. Although the
mesophase was impossible to be established from the one peak, it was tentatively identified as a Coltet
mesophase.
(Continued)
Copyright © 2013 World Scientific Publishing Company
J. Porphyrins Phthalocyanines 2013; 17: 273–282

274
M. SHIMIZU ET AL.
Table 4. (Continued).
Cub(Pn3m) at 160°C on
cooling
34.5
34.5
(3 2 1)
a = 129
30.7
30.7
29.6
21.9
—
(3 3 0)
(3 3 1)
(5 3 1)
#
2
9.6
1.9
2
ca. 8.9
ca. 4.6
ca. 3.4
34.5
—
#
—
h
(OH)PcCu: 11c
Col (F) at 120°C
34.5
19.9
17.2
13.0
11.5
—
(1 0 0)
(1 1 0)
(2 0 0)
(2 1 0)
(3 0 0)
#
h
a = 40.7
20.3
17.3
13.1
11.6
ca. 4.4
30.7
Col (F) at160°C
30.9
21.9
—
(1 0 0)
(1 1 0)
#
tet
a = 30.9
21.9
ca. 9.6
ca. 4.7
—
#
Cub(Pn3m) at 154°C on
cooling
38.4
38.4
(3 2 1)
a = 144
34.0
34.0
33.2
32.0
30.9
22.7
—
(3 3 0)
(3 3 1)
(4 2 0)
(3 3 2)
(6 2 1)
#
33.2
32.0
30.9
22.6
ca. 8.6
ca. 4.6
ca. 3.5
—
#
—
h
(
OH)PcH : 11d
M (R) at 70°C
35.9
—
—
—
—
2
x
If this mesophase is
2
2.4
Col (R), a = 35.9.
tet
ca. 9.5
.81
—
—
h2
h1
4
ca. 4.5
34.5
—
#
Col (F) at 110°C
34.5
24.4
—
(1 0 0)
(1 1 0)
#
tet
a = 34.5
24.4
ca. 4.5
Cub(Pn3m) at 130°C on
cooling
3
8.7
39.0
37.3
(3 1 1)
a = 129
37.1
(2 2 2)
(Continued)
Copyright © 2013 World Scientific Publishing Company
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DISCOTIC LIQUID CRYSTALS OF TRANSITION METAL COMPLEXES 48
275
Table 4. (Continued).
3
2
2.5
3.7
32.3
23.6
—
(4 0 0)
(5 2 1)
#
ca. 4.5
33.2
(OFba)PcCo: 12a
Col (R) at 85°C
32.5
23.0
14.5
(1 0 0)
(1 1 0)
(2 1 0)
tet
1
a = 32.5
h2 = ca. 9.5
h1 = 4.89
23.0
14.6
ca. 9.5
4.89
—
—
h2
h1
z = 0.88 for
ρ
= 1.0
ca.4.5
32.2
—
#
M at 118°C
—
—
x
2
1.2
—
—
If this mesophase is
Col (R) , a = 32.2
tet
2
13.3
—
—
ca. 9.5
—
h2
4
.89
—
h1
ca. 4.5
30.2
—
#
Col (F) at 160°C
30.6
21.6
10.8
—
(1 0 0)
(1 1 0)
(2 2 0)
#
tet
a = 30.6
21.6
1
1.0
ca. 4.6
Cub(Pn3m) at 155°C on
cooling
3
7.4
37.4
(3 2 1)
a = 140
32.9
32.9
32.0
29.8
22.2
—
(3 3 0)
(3 3 1)
(3 3 2)
(6 2 0)
#
3
2
2
2.0
9.8
2.2
ca. 9.9
ca. 4.7
ca. 3.4
—
#
—
h
3
2
2.2
1.7
32.2
22.8
(1 0 0)
(1 1 0)
(OFba)PcNi: 12b
Col (R) at 90°C
tet
a = 33.2
h2 = ca. 9.3
h1 = 4.85
13.5
11.0
14.4
10.7
—
(2 1 0)
(3 0 0)
h2
ca. 9.3
Z = 0.83 for
ρ
= 1.0
4.85
ca. 4.5
30.0
—
—
h1
#
Col (F) at 160°C
30.5
21.5
—
(1 0 0)
(1 1 0)
#
tet
a = 30.5
21.5
ca. 9.0
ca. 4.7
ca. 3.5
—
—
#
h
Cub(Pn3m) at 155°C on
cooling
3
9.1
39.0
37.7
(3 1 0)
a = 124
37.7
(3 1 1)
(Continued)
Copyright © 2013 World Scientific Publishing Company
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276
M. SHIMIZU ET AL.
Table 4. (Continued).
3
3
2
2
5.6
2.7
9.6
1.9
35.6
32.7
29.6
21.8
—
(2 2 2)
(3 2 1)
(3 3 0)
(4 4 0)
#
ca. 9.2
ca. 4.6
ca. 3.5
35.0
—
#
—
h
Col (R) at 90°C on cooling
35.0
20.6
17.9
13.5
—
(1 0 0)
(1 1 0)
(2 0 0)
(2 1 0)
h2
h
2
0.6
a = 41.3
h2 = ca. 9 5
h1 = 4.85
17.9
13.7
ca. 9.5
4.85
Z = 1.2 for
ρ
= 1.0
—
h1
ca. 4.4
—
#
(OFba)PcCu: 12c
Coltet (R) at 80°C
32.7
22.9
32.3
22.9
—
(1 0 0)
1
a = 32.3
h = 4.85
(1 1 0)
ca. 12
(2 2 0)+(3 0 0)
4
.85
—
h
#
ca. 4.3
—
Col (R) at 107°C
35.0
23.2
35.0
24.8
17.5
ca. 12
8.76
—
(1 0 0)
(1 1 0)
(2 0 0)
(2 2 0)+(3 0 0)
(4 0 0)
#
tet
2
a = 35.0
1
7.7
ca. 12
.73
8
ca. 4.4
31.1
Col (F) at 145°C
31.1
22.0
—
(1 0 0)
(1 1 0)
(2 2 0)+(3 0 0)
#
tet
a = 31.1
22.5
ca. 12
ca. 4.3
38.7
—
Cub(Pn3m) at 155°C
a = 128
38.7
37.0
33.9
30.6
—
(3 1 1)
(2 2 2)
(3 2 1)
(3 3 0)
#
37.1
3
4.0
0.7
3
ca. 12.2
ca.4.4
33.4
—
#
(
OFba)PcH : 12d
Col (R) at 80°C
33.4
23.5
15.0
11.1
—
(1 0 0)
(1 1 0)
(2 1 0)
(3 0 0)
h
2
tet
23.5
a = 33.4
h = 4.84
14.4
11.1
4.84
ca. 4.4
32.0
—
#
Col (F) at 110°C
32.0
22.6
(1 0 0)
(1 1 0)
tet
a = 32.0
22.9
(Continued)
Copyright © 2013 World Scientific Publishing Company
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DISCOTIC LIQUID CRYSTALS OF TRANSITION METAL COMPLEXES 48
277
Table 4. (Continued).
1
4.0
14.3
—
(2 1 0)
ca. 4.4
39.4
#
Cub(Pn3m) at 125°C
a = 138
39.3
34.7
31.5
30.6
21.8
—
(2 2 2)
34.8
(4 0 0)
3
3
2
1.5
0.7
1.9
(3 3 1)
(4 2 0)
(6 2 0)
ca. 12.8
ca. 4.4
33.2
#
—
#
(
OFbaC )PcCo: 3a
Coltet.1¶ at 65°C
a = 33.2
33.2
—
(1 0 0)
60
ca. 9.8
ca. 4.5
33.7
#
—
#
Coltet.2¶ at 90°C
a = 33.7
33.7
—
(1 0 0)
ca. 9.5
ca. 4.7
33.4
#
—
#
(
OFbaC )PcNi:3b
Coltet.o at 70°C
a = 33.4
33.4
15.0
—
(1 0 0)
6
0
14.2
(2 1 0)
h = 4.84
ca. 9.3
#
4.84
—
h
ca. 4.4
—
#
Coltet.d at 90°C
a = 33.2
33.2
33.2
23.5
—
(1 0 0)
23.6
(1 1 0)
ca. 9.2
ca. 4.5
33.2
#
—
#
(
OFbaC )PcCu: 3c
Coltet.o at 90°C
a = 33.2
33.2
23.5
—
(1 0 0)
60
23.4
(1 1 0)
h = 4.85
ca.11.5
#
4.85
—
h
ca. 4.5
—
#
(
OFbaC )PcH : 3d
Coltet.o at 75°C
34.0
34.0
24.0
—
(1 0 0)
60
2
23.9
(1 1 0)
a = 34.0
h = 4.81
ca. 9.1
4.81
#
h
#
—
ca. 4.5
—
appeared only on cooling from I.L. and it also gave
and ca. 9.3 Å (h : approximately two times of 4.85 Å),
2
a short stacking distance at ca. 3.5 Å (h). On further
whereas the higher temperature mesophase Col (F) at
tet
cooling below 110.3, the Col (F) mesophase appeared
160 °C gave a short stacking distance at ca. 3.5 Å (h),
as can be seen from Table 4. Very interestingly, the
Cub(Pn3m) mesophase of 12b also appeared only on
cooling from I.L. and it gave a short tacking distance
h
again via Col (F). The Col (F) mesophase gave again
tet
h
the broad peak at ca. 3.5 Å in the X-ray diffraction
pattern. On further cooling, the Col (F) mesophase was
h
suppercooled until room temperature and the stacking
at ca. 3.5 Å (h). On further cooling, Col (R) mesophase
h
distance at ca. 3.5 Å was maintained.
appeared and gave two stacking distances at 4.85 Å (h1)
For another example, the Col (R) mesophase of 12b
and ca. 9.5 Å (h ). These formation, deformation and
tet
2
at 90 °C also gave two stacking distances at 4.85 Å (h1)
reformation of the roof-top-shaped dimer are compatible
Copyright © 2013 World Scientific Publishing Company
J. Porphyrins Phthalocyanines 2013; 17: 277–282

278
M. SHIMIZU ET AL.
(
(
(
a) Parallel (cofacial) transition dipoles: blue-shift case
as a roof-top-shaped dimer stacking
distance for the Pc precursors, 11a–11d
and 12a–12d. However, as can be seen
from Fig. 4, the representative Pc-C60
dyad 3b did not show split Q-bands,
and the UV-vis spectra did not change
at all for the heating and cooling cycle.
Therefore, it can be concluded that
E"
E
E"
E'
Allowed
E'
Forbiden
G
Monomer
levels
Dimer
levels
3
b does not form the roof-top-shaped
dimers, and that the faceto-face stacking
shape maintains at all temperatures.
This phenomenon may be attributed
to the size of substituent group. The
precursors 11 and 12 having a relatively
small terminal substituent group of
hydroxyl or p-formyl benzoate hardly
move in more frozen alkyl chains at
lower temperatures. Accordingly, the
phthalocyanine core parts having the
relatively small terminal substituent
groups may tend to form roof-top-
shaped dimers in the lower temperature
mesophases of Col (R) and Col (R).
b) In-line transition dipoles: red-shift case
E"
E
Forbiden
Allowed
E"
E'
E'
G
Monomer
levels
Dimer
levels
c) Co-planar (slipped) transition dipoles: shift depends on angle q.
E"
tet
h
E'
On the other hand, these relatively
small terminal substituent group can
easily move in more melted alkyl
θ
chains in Col (F) mesophase at higher
tet
temperatures.As a result, phthalocyanine
core parts easily stack face-to-face in
the higher temperature mesophases of
0°
θ
54.7°
Dimer
levels
90°
Monomer
levels
Col (F) and Cub(Pn3m). Therefore, two
tet
(
d) Oblique (herringbone) transition dipoles: band-splitting case
longer stacking distances of 4.85 Å and
ca. 9.5 Å appear at lower temperature
mesophases, whereas a short stacking
distance at ca. 3.5 Å appears at higher
temperature mesophases. The Pc disks
of Pc-C60 dyad 3b having very bulky
terminal substituent group of fullerene
may not tilt to form roof-top-shaped
dimer due to the bulkiness of fullerene at
all the temperatures. Therefore, the dyad
E"
E
E"
Allowed
E'
h
E'
Allowed
G
Monomer
levels
Dimer
levels
3b may keep their stacking shape face-
Fig. 3. Kasha’s rules: exciton energy diagrams for various dimers
to-face at 4.85 Å.
Compared with the clearing points
with the UV-vis spectral changes of the thin film of 12b
mentioned above.
These unique phase structural changes of the
representative (OFba)PcNi (12b) derivative are illustrated
in Fig. 5, together with the phase transition sequence.
(cps) in Table 3 for all the present derivatives 11a–11d, 12a–
12d, and 3a–3d having a different terminal group, the cps of
12a–12d having benzoic acid group are lower by about 6 °C
on the average than those of 11a–11d having OH group. The
cps of 3a–3d having fullerene group is lower by about 67 °C
on the average than those of 12a–12d having benzoic acid
group. Therefore, the bulkier the terminal substituted group
becomes in an order of OH < benzoic acid < fullerene, the
Phase transition behavior of 3
As can be seen from Table 3, each of the Pc-C60
more Col mesophase only tends to appear.
tet
dyads, (OFbaC )PcM (3a–3d), shows only tetragonal
Additionally, the dyads 3a–3d only showed gradual
decomposition over their cps. It may be resulted from
chargetransferfromPcmoietytofullerene. Furtherstudies
are needed to clarify the origin of this decomposition.
6
0
columnar (Col ) mesophase(s). As can be seen from
tet
Table 4, the Coltet.o mesophases of 3b–3d gave a longer
stacking distance at ca. 4.85 Å, which was observed
Copyright © 2013 World Scientific Publishing Company
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DISCOTIC LIQUID CRYSTALS OF TRANSITION METAL COMPLEXES 48
279
contrast to these previous derivatives,
the present PcCu derivatives, (OH)PcM
(
11c), (OFba)PcM (12c) and (OFbaC )
60
PcM (3c), have no additional methoxy
group, as can be seen from Scheme
2
. Therefore, it is very interesting
for us to investigate the effect of an
additional methoxy group on their
phase transition behavior. Table 5 lists
the phase transition behavior of the
representative derivatives in both series
for comparison.
Comparing these clearing points, the
present PcCu compounds (11c, 12c and
3
c) give lower clearing points than the
previous methoxy-group-substituted
PcCu derivatives (8, 9 and 2): the cp of
1c is lower about 15 °C than that of 8;
1
the cp of 12c is about 10 °C than that
of 9; and the cp of 3c is about 70 °C
than that of 2. It is surprising for us that
removal of such a small methoxy group
from the big (OFbaC )PcM(OCH ) (2)
6
0
3
molecule significantly lowers the cp of
OFbaC )PcCu (3c) by about 70 °C in
(
6
0
comparison with that of 2 having the
methoxy group. Although the reason of
the cp lowering is not clear at the present
stage, we tentatively speculate it as
follows. The present PcCu compounds
(
11c, 12c and 3c) have larger open
space around Pc macrocycle than the
previous methoxy-group-substituted
PcCu derivatives (8, 9 and 2). Therefore,
the bulky terminal fullerene group of the
neighboring molecule may reach more
closely to the Pc macrocycle and perturb
the stacking of Pc disks to destroy the
columnar structure effectively at much
lower temperatures; it may cause the cp
lowering the present PcCu compounds
(11c, 12c and 3c).
As can be seen from Table 5, each of
the PcCu derivatives in both series shows
homeotropic alignment in the highest
temperature Col mesophase.
tet
Fig. 4. UV-vis spectra of the thin films of (OH)PcNi: 11b, (OFba)PcNi: 12b,
and (OFbaC )PcNi: 3b. Q = Q-band; SptQ = split Q-band; A = aggregated band
60
Homeotropic alignment
As can be seen from Table 3, each of the present novel
Pc compounds, 11 and 12, shows homeotropic alignment
Effect of an additional methoxy group directly
substituted to Pc core on clearing points
in the highest temperature Col mesophase. On the other
tet
In our previous work [25], we successfully synthe-
hand, each of the Pc-C60 dyads 3 shows homeotropic
alignment in all the Coltet mesophases. When perfect
homeotropic alignment can be achieved, it will give
complete darkness between cross polarizers. As can be
seen from the photomicrographs in Fig. 6, the (OFbaC )
sized PcCu derivatives, (OH)PcCu(OCH ) (8), (OFba)
3
PcCu(OCH ) (9) and (OFbaC )PcCu(OCH ) (2),
3
60
3
which have an additional methoxy group directly
substituted to Pc core, as shown in Scheme 1. In
6
0
Copyright © 2013 World Scientific Publishing Company
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280
M. SHIMIZU ET AL.
Fig. 5. The mechanism of phase transition for (OFba)PcNi (12b)
Table 5. Phase transition temperatures and enthalpy changes of the previous PuCu(OCH ) compounds (8, 9
3
and 2) and the present Cu compounds (11c, 12c and 3c).
T/ o
C
[∆H/ kJ mol -1
]
Compound
Phasea)
Phase
3.10]
[
(
OH)PcCu(OCH ): 8
3
3
0-70 [101]
142.3 [16.5]
153.1
154.1
very slow
182.6
Cub
I.L.
I.L.
K
Colh1
Colh2
Colh3
Coltet
82.0 [2.33] I.L.
53.3 [4.89]
137.5#
(
Pn3m)180.8
1
1
35.2#
167.9 [1.70]
Cub
9
4.0 [27.8]
1
(
OH)PcCu: 11c
K(R)
Col (F)
Mx
Coltet(F)
ca.138
h
ca.160 *
(
Pn3m)
[
17.8]
(
OFba)PcCu(OCH ): 9
3
4
0.6 [73.8]
73.8 [10.8]
116.5
ca. 122
170.8 [1.9]
K
Colob1
K(R)
Colob2
Colob3
Coltet
I.L.
4
6.0[90.0]
103.9[26.0]
108.7[5.75]
159.5[1.03]
(
OFba)PcCu: 12c
Coltet(R)2
Coltet(F)
I.L.
Coltet(R)1
Cub
ca.160
(Pn3m)
4
4.9 [69.5]
88.6 [20.4]
Coltet2
167.2 [10.0]
Coltet1
Coltet3
(
OFbaC60)PcCu(OCH ): 2
I.L.
3
4
4.0 [70.5]
8
8.3[27.2]
(
OFbaC60)PcCu: 3c
Coltet.o
+
K
I.L.(decomp.)
(
a) Phase nomenclature: K = crystal, Col = hexagonal columnar mesophase, Col = tetragonal ordered
h
t
e
t
.
o
columnar mesophase, Coltet.d = tetragonal disordered columnar mesophase, M = unidentified mesophase, Cub
x
=
cubic mesophase, I.L. = isotropic liquid, + = gradual decomposition over ca. 120°C, and  = mesophase
shawing homeotropic alignment.
Copyright © 2013 World Scientific Publishing Company
J. Porphyrins Phthalocyanines 2013; 17: 280–282

DISCOTIC LIQUID CRYSTALS OF TRANSITION METAL COMPLEXES 48
281
Fig. 6. Photomicrographs of the (OFbaC )PcM: (a) (OFbaC )PcCo: 3a at 90.0 °C on the first heating, (b) (OFbaC )PcNi: 3b at
60
60
60
8
5.0 °C on the first heating, (c) (OFbaC )PcCu: 3c at 87.0 °C on the first heating, and (d) (OFbaC )PcH : 3d at 87.0 °C on the first
6
0
6
0
2
heating (all the photos were taken under crossed polarizers)
PcM (M = Co, Ni, Cu, H ) dyads, 3a–3d, in the Coltet
hand, each of the Pc-C60 dyads 3 shows homeotropic
2
mesophases exhibited complete darkness characteristic
to perfect homeotropic alignment. It is noteworthy that 3c
and 3d show only one Coltet.o mesophase having ordered
stacking distance with perfect homeotropic alignment.
Such simple phase transition can contribute to maintain
stable performance in wide temperature range, when they
will be applied to organic thin film solar cells.
alignment in all the Col mesophases. Very interestingly,
tet
the Pc-C dyads 3c and 3d showed simple phase transition
60
with perfect homeotropic alignment in Coltet.o mesophase
having ordered stacking distance. These properties are
very suitable for organic solar cell fabrication.
Acknowledgements
This work is partially supported by Grant-in-Aid
for science research (Grant No. 2236012311) from the
Ministry of Education, Culture, Sports, Science and
Technology, Japan.
CONCLUSION
In this study, we have successfully prepared novel
PcM compounds, 11a–11d and 12a–12d, and Pc-C60
dyads 3a–3d (M = Co (a), Ni (b), Cu (c), metal free
REFERENCES
(
d)). The Pc-C dyads 3a–3d could be obtained in good
60
yields by Prato reaction. We established their unique
mesomorphism using temperature-dependent X-ray
diffraction measurements and temperature-dependent
electronic spectroscopy. It is surprising that a small
methoxy group largely affects the cps of these big
molecules, especially cps of Pc-C dyads. The cp of 3c
having no methoxy group is lower about 70 °C than that
of 2 having the methoxy group. Each of the present novel
Pc compounds, 11 and 12, shows homeotropic alignment
1. Kim JY and Bard AJ. Chem. Phys. Lett. 2004; 383:
11–15.
2. Nishizawa T, Tajima K and Hashimoto K. J. Mater.
Chem. 2007; 17: 2440–2445.
3. Roland T, Ramirez GH, Léonard J, Méry S and
Haacke S. J. Phys.: Conference Series 2011; 276:
012006(1–6).
4. Lincker F, Heinrich B, Bettignies R, Rannou P,
Pecaut J, Grevin B, Pron A, Donnio B and Dema-
drille R. J. Mater. Chem. 2011; 21: 5238–5247.
60
in the highest temperature Col mesophase. On the other
tet
Copyright © 2013 World Scientific Publishing Company
J. Porphyrins Phthalocyanines 2013; 17: 281–282

282
M. SHIMIZU ET AL.
5
. Barrau S, Heiser T, Richard F, Brochon C, Ngov
C, van de Wetering K, Hadziioannou G, Anokhin
DV and Ivanov DA. Macromolecules. 2008; 41:
20. Hayashi H, Nihashi W, Umeyama T, MatanoY, Seki
S, Shimizu Y and Imahori H. J. Am. Chem. Soc.
2011; 133: 10736–10739.
2
701–2710.
21. Bagui M, Dutta T, Chakraborty S, Melinger JS,
Zhong H, Keightley A and Peng Z. J. Phys. Chem.
A 2011; 115: 1579–1592.
22. Haverkate LA, Zbiri M, Johnson MR, Deme B, de
Groot HJM, Lefeber F, Kotlewski A, Picken SJ,
Mulder FM and Kearley GJ. J. Phys. Chem. B 2012;
116: 13098–13105.
6
7
. Kim DH, Lee BL, Moon H, Kang HM, Jeong EJ,
Park JI, Han KM, Lee S, Yoo BW, Koo BW, Kim
JY, Lee YH, Cho K, Becerril HA and Bao Z. J. Am.
Chem. Soc. 2009; 131: 6124–6132.
. Liang TC, Chiang IH,Yang PJ, Kekuda D, Chu CW
and Lin HC. J. Poly. Sci.: Part A Poly. Chem. 2009;
4
7: 5998–6013.
23. Ota (= Ohta) K. Jpn. Kokai Tokkyo Koho,
JP2011132180(A)-2011–07–07 (Priority number:
JP20090293501; Submission Date: 2009-12-24).
24. Ince M, Martinez-Diaz MV, Barbera J and Torres T.
J. Mater. Chem. 2011; 21: 1531–1536.
8
9
. Sommer M, Huettner S and Thelakkat M. J. Mater.
Chem. 2010; 20: 10788–10797.
. Yao K, Chen Y, Chen L, Li F, Li X, Ren X, Wang H
and Liu T. Macromolecules. 2011; 44: 2698–2706.
1
0. Yasuda T, Yonezawa K, Ito M, Kamioka H, Han L
25. Kamei T, Kato T, Itoh E and Ohta K. J. Porphyrins
Phthalocyanines 2012; 16: 1261–1275
and MoritomoY. J. Photopolym. Sci. Technol. 2012;
2
5: 271–276.
1. HanY, Chen L and ChenY. J. Poly. Sci. Poly. Chem.
012; published online: DOI: 10.1002/pola.26394.
2. Li F, Chen W and ChenY. J. Mater. Chem. 2012; 22:
259–6266.
26. Demus D, Goodby J, Gray GW, Spiess HW and Vill
V. Handbook of Liquid Crystals, Vol. 2B, Wiley-
VCH: New York, 1998; pp 693–798.
27. Kumar S. Chemistry of Discotic Liquid Crystals:
From Monomers to Polymers, CRC Press: 2010.
28. Ohta K, Nguyen-Tran H.-D, Tauchi L, Kanai Y,
Megumi T and Takagi Y. In The Handbook of Por-
phyrin Science, Vol. 12, Kadish KM, Smith KM and
Guilard R. (Eds.) World Scientific Publishing: Sin-
gapore, 2011; pp 1–120.
1
1
1
1
2
6
3. Bushby JR, Hamley IW, Liu Q, Lozman OR and
Lydon EJ. J Mater Chem. 2005; 15: 4429–4434.
4. Uchida S, Kude Y, Nishikitani Y and Ota (= Ohta)
K. Jpn. Kokai Tokkyo Koho. JP 2008214227(A)-
2
008-09-18 (Priority number: JP2007060604; Sub-
mission Date: 2007-03-09)
29. Hatsusaka K, Ohta K, Yamamoto I and Shirai H. J.
Mater. Chem. 2001; 11: 423–433.
30. Bingel C. Chem. Ber. 1993; 126: 1957–1959.
31. Maggini M, Scorrano G and Prato M. J. Am. Chem.
Soc. 1993; 115: 9798–9799.
1
1
1
1
5. Zhou X, Kang SW, Kumar S, Kulkarni RR, Cheng
SZD and Li Q. Chem. Mater. 2011; 20: 3551–3553.
6. de la Escosura A, Martınez-Dıaz MV, Barbera J and
Torres T. J. Org. Chem. 2008; 73: 1475–1480.
7. Tashiro K and Aida T. J. Amer. Chem. Soc. 2008;
32. Neises B and Steglish W. Angew. Chem. Int. Ed.
1978; 17: 522–524.
1
30: 13812–13813.
8. Geerts YH, Debever O, Amato C and Sergeyev S.
33. Hasebe H. Master Thesis, Sinshu University (1991);
Ema H. Master Thesis, Sinshu University (1988).
34. Kasha M, Rawls HR and El-Bayoumi MA. Pure.
Appl. Chem. 1965; 11: 371.
Beilstein J. Org. Chem., Beilstein J. Org. Chem.
2
009; 5: 1–9.
1
9. Thiebaut O, Bock H and Grelet E. J. Am. Chem.
Soc. 2010; 132: 6886–6887.
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