3732
Y. Liu et al. / Polymer 51 (2010) 3730e3735
Table 1
Table 2
Molecular weight and thermal properties of the polymers.
Optical data and fluorescence quantum yield of the polymers.
Polymers
Mw (ꢁ103)
Mn (ꢁ103)
PDI
Td (ꢀC)
Polymer
Absorption lmax (nm)
Emission lmax (nm)
VF (%)
P1
P2
P3
P4
P5
8.3
5.7
13.3
1.8
4.4
2.6
6.3
1.1
1.2
1.9
2.2
2.1
1.6
1.7
363
346
347
346
410
THF
Thin film
THF
Thin film
P1
P2
P3
P4
P5
379
388
404
365
383
378
398
406
372
400
488
498
505
484
505
491
502
509
499
525
37
42
46
21
21
2.0
2.4. General procedures for the preparation of the polymers
(P1eP5) [50]
P4: monomer 4 (111 mg, 0.22 mmol), monomer 1 (80 mg,
0.22 mmol), Pd(PPh3)4 (25 mg), Cs2CO3 (359 mg, 1.10 mmol). The
yellow powder 50 mg. Yield: 50%. 1H NMR (300 MHz, CDCl3,
The related monomer (1, 2 or 3), Pd(PPh3)4, Cs2CO3 were dis-
solved in dimethoxyethane at argon atmosphere. The mixture was
stirred at 65 ꢀC for 3 days. Then the reaction mixture was dropped
into 200 mL methanol through a cotton filter. The solid was
collected and purified by precipitation into methanol for three
times.
d
ppm): 7.49e6.71 (m, 18H), 4.37 (2H), 1.98 (2H), 1.50e1.26 (m, 6H),
0.91 (3H). 13C NMR (75 MHz, CDCl3,
d
ppm): 140.5, 128.7, 128.4,
128.2, 128.1, 128.0, 127.5, 127.2, 126.6, 123.0, 122.9, 108.6, 43.7, 31.8,
29.4, 27.3, 22.8, 14.2,
P5: monomer 4 (91 mg, 0.18 mmol), monomer 1 (84 mg,
0.18 mmol), Pd(PPh3)4 (21 mg), Cs2CO3 (293 mg, 0.90 mmol). The
yellow powder 70 mg. Yield: 70%. 1H NMR (300 MHz, CDCl3,
P1: 2,20-(9,9-dihexylfluorene-2,7-diyl)-bis(1,3,2-dioxaborinane)
(100.4 mg, 0.2 mmol), monomer 1 (73.2 mg, 0.2 mmol), Pd(PPh3)4
(23 mg), Cs2CO3 (326 mg, 1 mmol). The yellow powder 70 mg.
d
ppm): 8.16e6.91 (m, 22H), 4.37 (2H), 2.00e1.89 (2H), 1.33e1.28
(m, 6H), 0.94e0.87 (3H). 13C NMR (75 MHz, CDCl3,
d
ppm): 140.6,
Yield: 65%. 1H NMR (300 MHz, CDCl3,
d
ppm): 7.81 (d, 2H),
7.37e7.21 (m, 14H), 6.97 (s, 2H), 1.94 (t, 4H), 1.08e0.99 (m, 12H),
0.76 (m, 10H). 13C NMR (75 MHz, CDCl3,
ppm): 169.2, 151.3, 144.6,
133.4, 132.8, 128.4, 128.3, 128.1, 127.8, 127.6, 127.3, 126.5, 126.4,
126.2, 126.0, 125.8, 123.1, 108.7, 43.7, 31.8, 29.4, 27.3, 22.8, 14.2.
d
142.8, 140.5, 130.0, 128.4, 127.8, 126.1, 125.5, 119.8, 55.4, 40.5, 31.8,
29.9, 24.2, 22.8, 14.3.
3. Results and discussion
P2: 2, 20-(9,9-dihexylfluorene-2,7-diyl)-bis(1,3,2-dioxaborinane)
(126 mg, 0.25 mmol), monomer 2 (117 mg, 0.25 mmol), Pd(PPh3)4
(29 mg), Cs2CO3 (407 mg, 1.25 mmol). The green powder 125 mg.
3.1. Synthesis and characterization
Yield: 79%. 1H NMR (300 MHz, CDCl3,
d
ppm): 7.91e7.33 (m, 20H),
7.18 (s, 2H), 1.94 (4H), 1.01e0.68 (m, 22H). 13C NMR (75 MHz, CDCl3,
ppm): 151.4, 144.8, 140.7, 140.2, 139.2, 133.6, 130.2, 128.5, 127.9,
As shown in Scheme 1, (1Z, 3Z)-1,4-dibromo-1,4-diaryl-buta-
1,3-diene (monomer 1e3) was synthesized by the dimerization of
corresponding arylacetylene in the presence of PdCl2 and CuBr2
in the mixed solvents of toluene and MeCN [45]. In order to
adjust the photophysical properties, we selected three aromatic
acetylene as starting material to prepare the corresponding
(1Z, 3Z)-1,4-dibromo-1,4-diaryl-buta-1,3-diene. In addition, two
aromatic diborates, 2,20-(9,9-dihexylfluorene-2,7-diyl)-bis(1,3,2-
dioxaborinane) (4) and 9-hexyl-3,6-bis(4,4,5,5-tetramethyl-1,3,
2-dioxaborolan-2-yl)-9H-carbazole (5), were chosen to react
with monomer 1e3. All the new monomers were characterized
by NMR, MS and elemental analysis as in the Experimental
section.
d
127.7, 126.9, 126.3, 126.2, 125.7, 125.5, 119.9, 55.5, 40.5, 31.9, 29.9,
24.4, 22.8, 14.3.
P3: 2,20-(9,9-dihexylfluorene-2,7-diyl)-bis(1,3,2-dioxaborinane)
(92 mg, 0.14 mmol), monomer 1 (70 mg, 0.14 mmol), Pd(PPh3)4
(16 mg), Cs2CO3 (228 mg, 0.70 mmol). The yellow powder 72 mg.
Yield: 63%. 1H NMR (300 MHz, CDCl3,
d ppm): 7.88 (s, 2H), 7.64e7.50
(m, 6H), 7.41e7.25 (m, 10H), 7.12 (s, 2H), 7.07 (s, 2H), 2.01e1.88 (m,
12H), 1.07 (s, 12H), 0.76 (s, 10H), 0.31 (t, 12H). 13C NMR (75 MHz,
CDCl3,
d ppm): 149.9, 149.2, 148.7, 143.6, 140.5, 140.1, 139.9, 139.4,
138.2, 129.1, 125.8, 125.0, 123.9, 121.8, 18.6, 118.4, 54.8, 54.2, 39.4,
31.2, 30.8, 28.8, 23.2, 21.6, 13.1, 7.5.
The Suzuki reaction was applied to synthesize the polymers
(P1eP5) through the CeC coupling of (1Z, 3Z)-1,4-dibromo-1,4-
diaryl-buta-1,3-diene (1e3) with corresponding aromatic diborates
1.0
P1
P2
1.0
P1
P3
0.8
P2
P4
P3
P5
0.8
P4
0.6
P5
0.6
0.4
0.2
0.0
0.4
0.2
0.0
400
450
500
550
600
650
700
300
350
400
450
500
550
600
wavelength (nm)
wavelength (nm)
Fig. 1. UVevis absorption spectra of the polymers in THF (1.0 ꢁ 10ꢂ6 mol/L).
Fig. 2. Photoluminescence spectra of the polymers in THF (1.0 ꢁ 10ꢂ6 mol/L).