5
70
H. Sakamoto et al. / Reactive & Functional Polymers 71 (2011) 569–573
perature controller was used. MALDI-TOF and ESI mass spectra
were obtained using a AXIMA-TFR (SHIMADZU) and Finnigan LCQ™
Deca, respectively. NMR spectra were measured with a JNM-ECA
4
3 6
00 FT-NMR spectrometer (JEOL) using CDCl or DMSO-d solution
containing tetramethylsilane as an internal standard. Gas chro-
matograms were recorded on a CR5A Chromatopac (SHIMADZU)
and GC-14A gas chromatograph (SHIMADZU). Silica gel (100 mesh)
was used for column chromatography.
2
2
.2. Preparation of methacrylates of azacrown ethers
.2.1. General procedure
Fig. 1. Copolymers employed in this study.
To the CH
13], 4-(N,N-dimethylamino)pyridine and triethylamine in a 50
mL two-necked flask equipped with a dropping funnel, methacry-
loyl chloride in a dry CH Cl solution was added dropwise at 0 °C
2 2
Cl solution of N-(2-hydroxyethyl)azacrown ether
[
2.4. Polymerization of the azacrown ether methacrylate and
9-anthrylmethyl methacrylate
2
2
over 30 min, and the mixture was stirred for 4 h maintained at the
same temperature. After the reaction, the solvent was evaporated
in vacuo at ca. 30 °C. The methacrylate of the azacrown ether was
isolated with silica gel column chromatography using a mixed sol-
vent of chloroform and methanol (10/1) as the eluent.
2.4.1. General procedure
Copolymerization of the azacrown ether methacrylate and 9-
anthryl methacrylate, using AIBN as a radical initiator, was carried
out in THF in a sealed glass tube at 60 °C under vacuum conditions
for 24 h in a shaking incubator. The polymerization was monitored
1
by H NMR. After the reaction, the mixture became a yellowish gel,
2.2.2. 10-(2-Methacryloyloxyethyl)-1,4,7-trioxa-10-azacyclododecane
and this gel was poured into diethyl ether to purify the polymer by
reprecipitation. The composition of the obtained copolymer was
or aza-12-crown-4- methacrylate
N-(2-Hydroxyethyl)aza-12-crown-4 (1.1 g, 5 mmol), 4-(N,N-
dimethylamino)pyridine (0.06 g, 0.5 mmol), triethylamine (0.76 g,
1
estimated by H NMR and elemental analysis. The viscosity of
the copolymer dissolved in THF was measured using Ostwald’s vis-
cometer at 25 °C.
7
.5 mmol) and methacryloyl chloride (0.52 g, 5 mmol) were used,
and 0.263 g of the desired compound was obtained (yield: 24%).
1
3
H NMR (400 MHz, CDCl ): d 6.10 (s, 1H), 5.56 (s, 1H), 4.26 (t,
2
9
.4.2. Copolymer of aza-12-crown-4-methacrylate and
-anthrylmethyl methacrylate (1:1)
J = 6.0 Hz, 2H), 2.87 (t, J = 6.0 Hz, 2H), 3.63–3.68 (m, 12H), 2.81 (t,
J = 4.8 Hz, 4H), 1.94 (s, 3H) ppm.
Ã
Aza-12-crown-4-methacrylate (0.64 g, 2.2 mmol), 9-anthrylm-
ethyl methacrylate (0.61 g, 2.2 mmol), AIBN (3.5 mg, 0.021 mmol)
2
.2.3. 13-(2-Methacryloyloxyethyl)-1,4,7,10-tetraoxa-13-
and 2.0 mL of THF were used, and conversion to the polymer
azacyclotetradecane or aza-15- crown-5-methacrylate
N-(2-Hydroxyethyl)aza-15-crown-5 (2.63 g, 10 mmol), 4-(N,N-
dimethylamino)pyridine (0.12 g, 1.0 mmol), triethylamine 2.02 g,
1
yielded 0.152 g (12%). H NMR (400 MHz, CDCl
(
3
): d 7.51 (m), 4.04
] = 1.011. Ele-
brs), 3.65 (brs), 1.85 (brs), 1.02–0.84 (m) ppm. [
g
mental analysis data for the copolymer (1.3:1): Calc’d.: C, 60.63;
2
0 mmol) and methacryloyl chloride (2.08 g, 20 mmol) were used,
1
H, 6.55; N, 2.37. Found: C, 60.69; H, 6.80; N, 2.38.
and 0.66 g of the desired compound was obtained (yield: 20%). H
NMR (400 MHz, CDCl ): d 6.09 (s, 1H), 5.55 (s, 1H), 3.64 (m, 18H),
.89–2.76 (m, 6H), 1.94 (s, 3H) ppm.
Ã
(
(1:1) means that the initial mixing ratio of azacrown-methac-
3
rylate and anthrylmethyl methacrylate is 1:1).
2
2
.4.3. Copolymer of aza-12-crown-4-methacrylate and 9-
2
.2.4. 16-(2-Methacryloyloxyethyl)-1,4,7,10,13-pentaoxa-16-
⁄
anthrylmethyl methacrylate (5:1)
Aza-12-crown-4-methacrylate (0.64 g, 2.2 mmol), 9-anthrylm-
ethyl methacrylate (0.12 g, 0.4 mmol), AIBN (2.1 mg, 0.013 mmol)
azacyclooctadecane or aza-18-crown-6-methacrylate
N-(2-Hydroxyethyl)aza-18-crown-6 (0.46 g, 2.5 mmol), 4-(N,N-
dimethylamino)pyridine (0.03 g, 0.25 mmol), triethylamine
(
0.252 g, 2.5 mmol) and methacryloyl chloride (0.395 g, 3.8 mmol)
were used, and 0.19 g of the desired compound was obtained
1
(
1
6
yield: 20%). H NMR (400 MHz, CDCl
3
): d 6.10 (s, 1H), 5.55 (s,
H), 4.28 (t, J = 12.0 Hz, 2H), 3.75–3.57 (m, 20H), 2.88–2.80 (m,
H), 1.96 (t, J = 8.0 Hz, 3H) ppm.
2.3. Preparation of 9-anthrylmethyl methacrylate
2 2
To the CH Cl solution of 9-hydroxymethylanthracene (0.416 g,
2
mmol), 4-(N,N-dimethylamino)pyridine (0.024 g, 0.2 mmol) and
triethylamine (0.404 g, 4 mmol) in a 100 mL two-necked flask
equipped with a dropping funnel, methacryloyl chloride (0.416 g,
4
0
mmol) in 5 mL of dry CH
°C for 30 min, and the mixture was stirred for 4 h and maintained
2 2
Cl solution was added dropwise at
at the same temperature. After the reaction, the solvent was evap-
orated in vacuo at ca. 30 °C. The 9-anthrylmethyl methacrylate was
isolated with silica gel column chromatography using chloroform
as the eluent (0.441 g, yield: 80%). 1H NMR (400 MHz, CDCl
Fig. 2. Fluorescence spectral changes of copolymer 3 bearing an aza-18-crown-6
3
): d
.50 (s, 1H), 8.36 (d, 2H), 7.98 (d, 2H), 7.57 (t, 2H), 7.49 (t, 2H),
.22 (t, J = 6.0 Hz, 2H), 6.05 (s, 1H), 5.50 (s, 1H), 1.91 (s, 3H) ppm.
moiety. The vertical axis units are normalized against the maximum fluorescence
8
6
À3
À3
intensity in the absence of metal ions. [MClO
and [Anthracene unit] = 1.0 Â 10 mol dm in THF:H
4
] = 1.0 Â 10 mol dm (M = Li, Na, K)
À5
À3
2
O = 10:1; kex = 266 nm.