106
J. Wang, L.M. Leung / Dyes and Pigments 99 (2013) 105e115
prepared with the goals of disrupting the symmetry for recrystal-
lization and eliminating the chance of phase separation of the
dopant from the matrix and at the same time without significantly
altering the overall electrical (LUMO/HOMO) and optical properties
determined in THF at room temperature against quinine sulfate
(0.1 M H SO ) standard ( ¼ 0.48; ¼ 334 nm,
¼ 313 nm,
2
4
l
4
F
l
4
F
¼ 0.56) [48]. CV measurements were performed on a BAS CV-
50W electrochemical analyzer. All measurements were carried
out at room temperature with a conventional three-electrode
configuration including a platinum working electrode, an auxil-
iary electrode and an Ag/AgCl reference electrode. The supporting
electrolyte was 0.1 M tetrabutylammonium hexafluorophosphate
(
CIEx,y).
In our previous work, a blue emitting vinyl polymer poly(9,10-
di(1-naphthalenyl)-2-vinylanthracene) (P(ADN)) based on 2-
methyl-9,10-di(1-naphthalenyl)anthracene (MADN) had shown to
possess excellent thermal stability and retained most of the pho-
toluminescent & electrochemical properties of the parent small
molecule MADN [47]. However, the solubility of P(ADN) dimin-
ished when its molecular weight (MW) became higher than 13,000.
In this paper, two novel blue fluorescent monomers Vinyl-2ADN
and Vinyl-3ADQ rooted from the basic molecules 2MADN and
4 6
([Bu N]PF ) dissolved in acetonitrile (ACN). The measurements
were calibrated with an internal standard, ferrocene/ferrocenium
þ
þ
(Fc/Fc ) redox couple (taken HOMO of Fc/Fc ¼ ꢁ4.8 eV).
2.2. Synthesis
3
MADQ were synthesized. Their polymers P(2ADN) and P(3ADQ)
2.2.1. 2-Methyl-1,4,4a,9a-tetrahydroanthracene-9,10-dione (Nad)
Nad was synthesized by the DielseAlder reaction. 1,4-
Naphthaquinone (10.00 g, 63.20 mmol) and isoprene (12.90 g,
189.60 mmol) were dissolved in 150 mL of methanol. The reaction
solution was refluxed and stirred overnight under open atmo-
sphere. Most of the solutions were evaporated under reduced
were prepared using free radical solution addition polymerization.
Besides of the consideration of the steric effects, the replacement of
the heteroatom N to CH at the C-3 position of the 2-naphthalenyl
group also enhance the solubility for P(3ADQ). The chemistry and
physical properties of the intermediates, the monomers and the
resulting polymers were characterized using, nuclear magnetic
resonance (NMR) spectroscopy, gel permeation chromatography
pressure and the residue was filtered to obtain a white solid (95%
1
yield). H NMR (400 MHz, CDCl
3
):
d
(ppm) 8.06e8.02 (m, 2H), 7.77e
(
GPC), fourier transform infrared (FT-IR) spectroscopy, thermogra-
7.73 (m, 2H), 5.44e5.41 (m, 1H), 3.44e3.32 (m, 2H), 2.54e2.42 (m,
13
vimetric analysis (TGA), differential scanning calorimetry (DSC),
matrix-assisted laser desorption ionization time-of-flight mass
spectrometry (MALDI-TOF MS), ultravioletevisible (UVeVis) spec-
troscopy, PL spectroscopy, cyclic voltammetry (CV) and quantum
yield measurements.
2H), 2.26e2.15 (m, 2H), 1.69 (d, J ¼ 0.56 Hz, 3H). C NMR (100 MHz,
CDCl ): (ppm) 193.26, 192.96, 129.02, 128.80, 128.75, 126.60,
3
d
121.61, 121.58, 113.30, 41.85, 41.19, 23.72, 19.59, 18.22. MS (MALDI-
TOF) m/z ¼ 222.1077 (M þ H).
2.2.2. 2-Methyl-9,10-anthracenequinone (MAq)
2
. Experimental
To a 250 mL two-mouth round bottom flask, the compound Nad
(5.00 g, 22.10 mmol) and KOH (4.00 g,100.00 mmol) were dissolved
2.1. Materials and instruments
in 100 mL methanol. Compress air was introduced to oxidize the
Nad. The solution was heated to 45 C and stirred overnight. The
ꢀ
Unless specified otherwise, all reactions were carried out under
products were filtered and washed by methanol to obtain a
1
the nitrogen atmosphere using standard Schlenk techniques. The
yellowish solid (98% yield). H NMR (400 MHz, CDCl
3
):
d
(ppm)
ꢀ
glassware was dried in a 120 C oven. The analytical grade solvents
8.32e8.28 (m, 2H), 8.21 (d, J ¼ 7.92 Hz, 1H), 8.11 (d, J ¼ 0.44 Hz, 1H),
7.82e7.77 (m, 2H), 7.60 (dd, J ¼ 7.96 Hz, 1H), 2.54 (s,
¼ 1.04 Hz, J
3H). C NMR (100 MHz, CDCl ): (ppm) 183.37, 182.94, 145.27,
were purified by distillation with appropriate drying agents and
1
2
13
blanketed with inert nitrogen atmosphere prior to use. Benzoyl
3
d
0
peroxide (BPO) and 2, 2 -azobisisobutyronitrile (AIBN) were
134.92, 134.03, 133.91, 133.54, 133.51, 133.33, 131.23, 127.47, 127.41,
recrystallized in a chloroform/methanol mixed solvent before use.
All other chemicals (analytical grade) were purchased from com-
mercial sources and were used as received.
127.13, 127.11, 21.91. MS (MALDI-TOF) m/z ¼ 222.0644 (Mþ).
2.2.3. 2-Methylanthracene (MA)
Solid-state FT-IR spectra were recorded on a Nicolet Magna 550
Series II FT-IR spectrometer using KBr pellets. The H and C NMR
spectra were measured on a Bruker-AF301 AT 400 MHz spec-
To a 250 mL round bottom flask, MAq (4.00 g, 18.00 mmol), zinc
powder (3.50 g, 72.00 mmol), cupric sulfate pentahydrate (0.10 g,
0.40 mmol) and ammonia solution (200.00 g) were added. The
1
13
ꢀ
trometer using deuterated solvents (CDCl
3
or dimethyl sulfoxide-
mixture was heated to 85 C and it turned from red to colorless.
d (DMSO-d)) and tetramethylsilane as the internal standard.
MALDI-TOF MS spectra were carried out and recorded using an
Autoflex Bruker MALDI-TOF mass spectrometer. The molecular
weights and polydispersity of the homopolymers were determined
by GPC on an HP 1050 series HPLC with a visible wavelength and
fluorescent detectors (at 254 nm) using tetrahydrofuran (THF) as
the mobile phase (HPLC column: Jordi Gel GBR Mixed Bed,
After filtration, the residue was washed by acetone. The acetone
was then evaporated and methanol was added, a white solid was
1
precipitated by adding conc. HCl (87% yield). H NMR (400 MHz,
3
CDCl ): d (ppm) 8.37 (s, 1H), 8.31 (s, 1H), 7.99e7.96 (m, 2H), 7.91 (d,
J ¼ 8.68 Hz, 1H), 7.75 (s, 1H), 7.45e7.40 (m, 2H), 7.31 (dd,
13
J
1
¼ 1.60 Hz, J
2
¼ 8.68 Hz, 1H), 2.55 (d, J ¼ 0.40 Hz, 3H). C NMR
): (ppm) 134.88, 131.95, 131.80, 131.18, 130.29,
(100 MHz, CDCl
3
d
3
00 mm ꢂ 7.8 mm). The GPC results were calibrated against
128.22, 128.15, 128.03, 127.93, 126.29, 125.91, 125.20, 125.13, 124.88,
21.98. MS (MALDI-TOF) m/z ¼ 193.1024 (M þ H).
polystyrene standards with molecular weight at 1350 (PDI ¼ 1.03),
2
8,000 (PDI ¼ 1.01), 87,000 (PDI ¼ 1.02) and 410,000 (PDI ¼ 1.03).
Thermal analyses were carried out on a PerkineElmer Pyris Dia-
mond DSC and PerkineElmer TGA6 thermal analyzers at a heating
2.2.4. 9,10-Dibromo-2-methylanthracene (MADBr)
To a 250 mL round bottom flask, the compound MA (1.00 g,
5.20 mmol), n-bromosuccinimide (NBS) (2.23 g, 12.00 mmol) and
ꢀ
ꢀ
rate of 40 C/min (DSC) and 20 C/min (TGA) under nitrogen purge,
respectively. UVevis absorption spectra were obtained with a
Varian Cary 200 spectrophotometer both in THF solution and in
solid-state thin film. The PL spectroscopy was measured on a
PerkineElmer LS55 Luminescence Spectrometer both in THF solu-
tion and in solid-state thin film. The fluorescence quantum effi-
ciencies of the monomers and their homopolymers were
200 mL trifluoroacetic acid was dissolved in 20 mL chloroform. The
solution was stirred overnight at room temperature. After reaction,
most of chloroform was evaporated, methanol was then added, a
1
yellow needle-like crystal was obtained (90% yield). H NMR
(400 MHz, CDCl
1H), 8.34 (s, 1H), 7.64e7.58 (m, 2H), 7.46 (dd, J
3
):
d
(ppm) 8.58e8.54 (m, 2H), 8.48 (d, J ¼ 9.22 Hz,
1
¼ 1.52 Hz,