Synthesis and properties of optically active 6,6′-didodecyl-1,1′-binaphthyl-phthalocyanine linked through crown ether units

Article abstract of DOI:10.1016/S0040-4039(01)01477-0

A novel optically active 6,6′-didodecyl-1,1′-binaphthyl-metallophthalocyanine linked through crown ether units ((S)-Pc) has been synthesized. A stable monolayer of (S)-Pc that is able to bind metal ions can be formed at the air-water interface. Nonlinear

Full text of DOI:10.1016/S0040-4039(01)01477-0

TETRAHEDRON
LETTERS
Pergamon
Tetrahedron Letters 42 (2001) 7083–7086
Synthesis and properties of optically active
6
,6%-didodecyl-1,1%-binaphthyl-phthalocyanine linked through
crown ether units
Hongwei Liu, Yaohu Liu, Minghua Liu, Chuanfu Chen and Fu Xi*
Center for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, PR China
Received 30 April 2001; revised 2 August 2001; accepted 7 August 2001
Abstract—A novel optically active 6,6%-didodecyl-1,1%-binaphthyl-metallophthalocyanine linked through crown ether units ((S)-Pc)
has been synthesized. A stable monolayer of (S)-Pc that is able to bind metal ions can be formed at the air–water interface.
Nonlinear absorption and optical limiting behavior of (S)-Pc have also been observed. © 2001 Elsevier Science Ltd. All rights
reserved.
6
Phthalocyanines have been extensively studied for their
remarkable optical and electrical behavior. In the last
Then (S)-10 was prepared by the reaction of (S)-4 and
9 in boiling n-BuOH in the presence of NaOH. Finally,
1
6
decade, optically active phthalocyanines have attracted
(S)-Pc was obtained directly by heating (S)-10 in
DMF with a large excess of copper cyanide at 130°C
for 24 h. H NMR, UV–vis, CD spectra and MALDI-
TOF MS support the structure of (S)-Pc as proposed.
According to the literature, the chiral configuration of
1,1%-binaphthyl molecules is relatively stable at higher
temperatures over extended periods of time. The
design of the synthetic procedure shown in Scheme 2
was based on extensively employed literature reaction
2
–4
much attention. Recently, we have been dealing with
the design and synthesis of a series of optically active
phthalocyanines, whose performance in constructing
highly ordered thin films and exhibiting excellent opti-
cal limiting have been investigated. Herein, we wish to
report the synthesis and properties of a novel optically
active copper phthalocyanine.
1
8
The structure of optically active copper phthalocyanine
(
S)-Pc is shown in Scheme 1. It can be considered as
consisting of a phthalocyanine core, four 20-crown-6
rings, and eight dodecyl chains linked through binaph-
thyl units to the crown ether rings. The synthesis of
(
S)-Pc is shown in Scheme 2. The optically active
crown ether (S)-10 was constructed from two building
5
6
blocks of compound 9 and (S)-4. The starting mate-
rial for the preparation of (S)-4 was optically active
(
S)-1, which was brominated to give (S)-2 and subse-
7
quently converted to (S)-3 by treatment with
chloromethyl ether. (S)-4 was obtained by in situ
deprotection after the reaction of (S)-3 with dodecyl-
magnesium bromide in dry ether using (dppp)NiCl as
2
the catalyst. The building block 9 was synthesized from
catechol 5 as a starting material. Catechol 5 was brom-
inated and then alkylated with diethyleneglycol
monotosylate 7 to produce compound 8, which was
converted into 9 by tosylation with p-tosyl chloride.
*
Corresponding author. Tel.: ++86-010-62557907; fax: ++86-010-
2559373; e-mail: xifu@infoc3.icas.ac.cn
6
Scheme 1. The structure of the optically active (S)-Pc.
0
040-4039/01/$ - see front matter © 2001 Elsevier Science Ltd. All rights reserved.
PII: S0040-4039(01)01477-0

7
084
H. Liu et al. / Tetrahedron Letters 42 (2001) 7083–7086
+
absence or presence of K . From Fig. 2, it was also
found that the crown ether rings of (S)-Pc have the
ability to bind metal ions that can be demonstrated by
the limiting molecular areas. The limiting molecular
areas obtained by extrapolating the linear part of the
isotherm to zero pressure are 340, 345, 425, 450, and
2
8
00 A
,
/molecule for curve A, B, C, D, and E, respec-
tively. It is clear that the limiting molecular areas
increase as the concentration of K increases. When
+
pure water is the subphase, the Pc core of (S)-Pc has a
diameter of 20.8 A
molecular area of 340 A
that the molecules of (S)-Pc in monolayers are stacked
,
, which was deduced from the large
2
,
/molecule. This result means
Scheme 2. The synthesis of the optically active (S)-Pc.
2
,5
conditions. It was confirmed that there was very little
9
or no rotational loss of optically activity.
The CD and UV–vis spectra of (S)-Pc in THF are
displayed in Fig. 1. The UV–vis spectrum shows the
two characteristic intense bands of metal phthalocya-
nine, the Q and the B band, both correlated to p–p*
transitions. The CD spectrum of (S)-Pc in THF (1×
Figure 1. (a) CD and (b) UV–vis spectra of (S)-Pc in THF
and thin film.
−
4
1
2
0
M) exhibits strong absorptions in the region of
1
20–250 nm owing to the B transition of the naphtha-
b
lene moiety. In addition, the Soret band and Q band
are observed, which are due to the introduction of the
optically active binaphthyl moieties onto the periphery
2
c
of the phthalocyanine. It can also be seen that (S)-Pc
exhibits a mainly negative CD envelope resulting from
the main Soret and Q bands. Furthermore, the binaph-
thyl moiety of (S)-Pc is right-handed, which is demon-
10
strated by the Cotton effect in the 220–250 nm region.
In Fig. 2, curves A–E show the surface pressure–area
isotherm of the spreading monolayers of (S)-Pc fabri-
−
4
cated from a chloroform solution (1×10 M) with
water as the subphase in the absence and presence of
potassium chloride (KCl). The (S)-Pc was observed to
form stable films up to 40 mN/m whether in the
Figure 2. Surface pressure–area isotherms of the monolayers
of (S)-Pc at the air–water interface in the absence and pres-
ence of K at 20°C.
+

H. Liu et al. / Tetrahedron Letters 42 (2001) 7083–7086
7085
in a side-on arrangement with the substituents oriented
away from the water surface, which is in line with the
conformation of the CPK model. Furthermore, when
potassium chloride is used as the subphase, the limiting
molecular area is larger than that observed when water
is used as the subphase. The reason may be that, when
binding metal ions, the crown ether rings are dragged
back to the water surface resulting in the molecular
area increase.
the solutions have linear transmission. While at high
input fluence, the nonlinear transmission is observed
between the output and input fluence indicating that
optical limiting performance occurs. The optical limit-
ing thresholds of (S)-Pc in chloroform are 800, 490, 350
2
and 160 mJ/cm , at the linear transmittance of 73, 64,
4
7 and 31%, respectively. The thresholds decrease as
the concentration of (S)-Pc increases which may be
ascribed to reverse saturable absorption (RSA). The
nonlinear absorption of (S)-Pc was investigated by
open aperture Z-scan measurements as shown in Fig. 4.
The large transmission decreases about 80% at the
focus point indicating an RSA behavior. Moreover, the
The CD and UV–vis spectra of transferred LB films of
(
S)-Pc are shown in Fig. 1. In the UV–vis spectrum, the
Q band is red shifted to 690 nm in comparison with
that in THF. In the CD spectrum, the intense Q band
is observed at 698 nm, and is obviously different from
that in THF, though the sign of the Cotton effect is
identical. These large changes in the CD and UV–vis
spectra in comparison with those in THF may be
attributed to the packed arrangement of (S)-Pc
molecules in the side-on orientation.
1
1
Z-scan data can be fitted well by the equation of the
RSA model. The solid curve in Fig. 4 shows the best fit
of the unapertured data, which also demonstrates the
OL is the result of RSA.
Acknowledgements
The optical limiting (OL) properties of (S)-Pc with
different linear transmittance in chloroform are shown
in Fig. 3. It can be seen that at very low laser energy,
We greatly appreciate the help from Professor C. Ye,
Professor P. J. Wu, Dr. P. Wang, and Dr. S. Zhang for
the detection of nonlinear absorption and optical limit-
ing behavior in the samples. This project is supported
by the National Science Foundation of China.
References
1
. For reviews, see: (a) van Nostrum, C. F.; Nolte, R. J. M.
J. Chem. Soc., Chem. Commun. 1996, 2385; (b) da la
Torre, G.; V a´ zquez, P.; Agull o´ -L o´ pez, F.; Torres, T. J.
Mater. Chem. 1998, 8, 1671; (c) da la Torre, G.;
Claessens, C. G.; Torres, T. Eur. J. Org. Chem. 2000,
2812 and references cited therein.
2
. (a) Kobayashi, N.; Kobayashi, Y.; Osa, T. J. Am. Chem.
Soc. 1993, 115, 10994; (b) Kobayashi, N. Chem. Com-
mun. 1998, 487; (c) Kobayashi, N.; Higashi, R.; Titeca, B.
C.; Lamote, F.; Ceulemans, A. J. Am. Chem. Soc. 1999,
1
21, 12018.
. Engelkamp, H.; Middelbeek, S.; Nolte, R. J. M. Science
999, 284, 785.
Figure 3. Optical limiting properties of (S)-Pc at different
linear transmittance for 10 ns, 532 nm laser pulses in a 1 mm
quartz cell.
3
4
1
. Fox, J. M.; Katz, T. J.; Elshocht, S. V.; Verbiest, T.;
Kauranen, M.; Persoons, A.; Thongpanchang, T.;
Krauss, T.; Brus, L. J. Am. Chem. Soc. 1999, 121, 3453.
. Liu, H. W.; Chen, C. F.; Ai, M.; Gong, A. J.; Jiang, J.;
Xi, F. Tetrahedron: Asymmetry 2000, 11, 4915.
5
6
1
. For (S)-4: mp 73–74°C; [h] =+58.4 (c 0.514, CHCl ); H
D
3
NMR (CDCl , 300 MHz): l 0.87 (t, J=6.6 Hz, 6H,
3
CH ), 1.24–1.72 (m, 40H, CH ), 2.71 (t, J=7.6 Hz, 4H,
3
2
CH ), 4.97 (s, 2H, OH), 7.06 (d, J7,8=8.6 Hz, 2H, ArH8),
2
7
.14 (dd, J7,8=8.6 Hz, J5,7=1.2 Hz, 2H, ArH ), 7.32 (d,
7
J3,4=8.9 Hz, 2H, ArH ), 7.65 (s, 2H, ArH ), 7.88 (d,
3
5
J3,4=8.9 Hz, 2H, ArH ). Anal. calcd for C H O : C,
4
44 62
2
8
4.89; H, 9.97. Found: C, 84.67; H, 10.16%.
1
For (S)-10: [h] =−82.7° (c 1.46, CHCl ); H NMR
D
3
(
CDCl , 300 MHz): l 0.87 (t, J=6.5 Hz, 6H, CH ),
3
3
1.25–1.78 (m, 40H, CH ), 2.69 (t, J=7.6 Hz, 4H, CH ),
2 2
3
.48–4.18 (m, 16H, OCH ), 7.03–7.06 (m, 6H, ArH), 7.37
2
Figure 4. Open aperture Z-scan for (S)-Pc in chloroform at
(d, J3,4=9 Hz, 2H, ArH ), 7.58 (s, 2H, ArH ), 7.75 (d,
3
5
the transmittance of 64%.
J3,4=9 Hz, 2H, ArH ). Anal. calcd for C H Br O : C,
4 58 78 2 6

7
086
H. Liu et al. / Tetrahedron Letters 42 (2001) 7083–7086
7.57; H, 7.63. Found: C, 67.32; H, 7.90%. m/z (MALDI-
6
during the reaction, the optical stability of compound
(S)-10 was measured by subjecting the (S)-10 to the same
reaction conditions which were used in the preparation of
the optically active (S)-Pc as follows: a solution of (S)-10
in DMF was heated with stirring under nitrogen at 130°C
for 24 h, then DMF was removed at the reduced pres-
sure. It is found that the specific rotation of the recovered
+
TOF) 1028.45 (M ).
For (S)-Pc: decomp. 324°C; H NMR (CDCl , 300
1
3
MHz): l 0.87 (br, s, 24H, CH ), 1.25–1.78 (br, m, 160H,
3
CH ), 2.65 (br, s, 16H, CH ), 3.2–4.2 (br, m, 64H,
2
2
OCH ), 7.0–7.8 (br, m, 48H, ArH); m/z calcd for
2
C240H312CuN O : M, 3753.27. Found: (MALDI-TOF)
8
24
+
3
753.29 (M ).
. Hu, Q. S.; Zheng, X. F.; Pu, L. J. Org. Chem. 1996, 61,
200.
(S)-10 is [h] =−82.5°. Comparing with the original spe-
D
7
8
cific rotation of (S)-10 ([h] =−82.7°), it is clear that no
D
5
obvious rotational loss is occurred.
. Kyba, E. P.; Gokel, G. W.; Jong, F. D.; Koga, K.; Sousa,
L. R.; Siegel, M. G.; Kaplan, L.; Sogah, G. D. Y.; Cram,
D. J. J. Org. Chem. 1977, 42, 4173.
10. Harada, N.; Nakanishi, K. Circular Dichromic Spec-
troscopy, Exciton Coupling in Organic Stereochemistry;
University Science Books: New York, 1983.
11. Wood, G. L.; Miller, M. J.; Mott, A. G. Opt. Lett. 1995,
20, 973.
9. In order to demonstrate the target optically active
phthalocyanine has not undergone partial racemization