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ARTICLE
naphthalene-2,7-diyl core on the electrochemical and electro-
chromic properties of the polyamides was investigated by
comparing with those of (OMe)2TPPA-derived polyamides.
for about 24 h. After cooling, the mixture was poured into
400 mL of methanol, and the precipitated product was col-
lected by filtration. The crude product was thoroughly
washed by methanol to obtain 10.5 g (85%) of brown pow-
der. IR (KBr): 1585, 1308 cm21 (2NO2 stretch).
EXPERIMENTAL
1H NMR (600 MHz, DMSO-d6, d, ppm): 8.05 (d, J 5 9.6 Hz,
4H, Hg), 7.95 (d, J 5 9.0 Hz, 2H, Ha), 7.65 (d, J 5 2.4 Hz, 2H,
Hc), 7.35 (dd, J 5 9.0, 2.4 Hz, 2H, Hb), 7.24 (d, J 5 9.0 Hz, 4H,
Hd), 7.02 (d, J 5 9.0 Hz, 4H, He), 6.84 (d, J 5 9.6 Hz, 4H, Hf),
3.78 (s, 6H, 2OCH3). 13C NMR (150 MHz, DMSO-d6, d, ppm):
157.68, 153.41, 143.43, 138.89, 137.47, 134.83, 129.61,
128.79, 128.70, 125.56, 124.71, 122.98, 116.72, 115.51,
55.30 (codes of the hydrogen and carbon atoms: see Fig. 1).
ANAL. CALCD. for C36H28N4O6 (612.64): C, 70.58%; H, 4.61%,
N, 9.14%. Found: C, 70.02%; H, 4.35%; N, 8.95%.
Materials
N,N’-Bis(4-methoxyphenyl)-2,7-naphthalenediamine
(1)
(m.p. 5 175 2 177 8C) was synthesized by condensation of
2,7-dihydroxynaphthalene (Acros) with p-anisidine (Acros) in
the presence of catalytic amounts of iodine by the Knoevena-
gel’s method.21 p-Fluoronitrobenzene (Acros), cesium fluo-
ride (CsF) (Acros), 10% palladium on charcoal (Pd/C)
(Acros), and 99% hydrazine monohydrate (TCI) were used
without further purification. Dimethyl sulfoxide (DMSO)
(Tedia), N,N-dimethylacetamide (DMAc) (Tedia), pyridine
(Py) (Wako), and N-methyl-2-pyrrolidone (NMP) (Tedia)
were dried over calcium hydride for 24 h, distilled under
reduced pressure, and stored over 4 Å molecular sieves in
sealed bottles. Triphenyl phosphite (TPP) (TCI) was used as
received from the supplier. Commercially obtained calcium
chloride (CaCl2) was dried under vacuum at 180 8C for 3 h
prior to use. The aromatic dicarboxylic acid monomers
including 4,4’-biphenyldicarboxylic acid (4a) (Aldrich), 4,4’-
dicarboxydiphenyl ether (4b) (TCI), bis(4-carboxyphenyl)
sulfone (4c) (TCI), and 2,2-bis(4-carboxyphenyl)hexafluoro-
propane (4d) (TCI) were used as received from commercial
sources. Tetrabutylammonium perchlorate (Bu4NClO4) (TCI)
was recrystallized twice from ethyl acetate under nitrogen
atmosphere and then dried in vacuo prior to use. All other
reagents and solvents were used as received from commer-
cial sources.
N,N’-Bis(4-Aminophenyl)-N,N’-Bis(4-Methoxyphenyl)-2,7-
Naphthalenediamine (3)
In a 250-mL three-neck round-bottomed flask equipped with
a stirring bar under nitrogen atmosphere, 2.00 g (3.26
mmol) of dinitro compound 2 and 0.15 g of 10% Pd/C were
dispersed in 150 mL of ethanol. The suspension solution
was heated to reflux, and 2 mL of hydrazine monohydrate
was added slowly to the mixture. After a further 24 h of
reflux, the solution was filtered to remove Pd/C, and the fil-
trate was cooled under nitrogen atmosphere. The precipitat-
ed product was collected by filtration and dried in vacuo at
80 8C to give 1.44 g (80% in yield) of pale yellow-green
powder; mp 5 188 2 190 8C (by DSC). IR (KBr): 3448,
3368 cm21 (2NH2 stretch).
1H NMR (600 MHz, DMSO-d6, d, ppm): 7.46 (d, J 5 8.9 Hz,
2H, Ha), 6.98 (d, J 5 8.9 Hz, 4H, Hd), 6.86 (d, J 5 9.0 Hz, 4H,
He), 6.80 (d, J 5 8.6 Hz, 4H, Hf), 6.78 (dd, J 5 8.9, 2.3 Hz, 2H,
Hb), 6.56 (d, J 5 2.3 Hz, 2H, Hc), 6.55 (d, J 5 8.6 Hz, 4H, Hg),
5.00 (s, 4H, 2NH2), 3.73 (s, 6H, 2OCH3). 13C NMR (150
MHz, DMSO-d6, d, ppm): 155.20, 147.14, 145.81, 140.58,
135.73, 135.25, 127.92, 127.49, 125.88, 122.83, 117.99,
114.90, 114.66, 111.83, 55.13 (codes of the hydrogen and
carbon atoms: see Fig. 1). ANAL. CALCD. for C36H32N4O2
(552.91): C, 78.20%; H, 5.83%, N, 10.13%. Found: C,
78.02%; H, 5.35%; N, 9.87%.
Monomer Synthesis
N,N’-Bis(4-Methoxyphenyl)-2,7-Naphthalenediamine (1)
In a 100-mL three-necked round-bottom flask equipped with
a Dean-Stark trap, a mixture of 16 g (0.1 mol) of 2,7-dihy-
droxynaphthalene, 24 g (0.2 mol) of p-anisidine and 1.0 g
(7 mmol) of iodine in 40 mL of xylene was heated at
160 8C for about 24 h. After cooling to around 90 to
100 8C, the mixture was poured into 200 mL of ethanol,
and the precipitated product was collected by filtration.
Recrystallization from ethanol yielded 30 g (81%) of gray
crystals with melting point of 176 to 179 8C (by DSC). IR
(KBr): 3411 (2NH2 stretch), 2950, 2835 cm21 (methoxy,
C2H stretch).
Synthesis of Model Compound
A mixture of 0.1105 g (0.2 mmol) of diamine monomer 3,
0.0488 g (0.4 mmol) of benzoic acid, 0.15 g of anhydrous
calcium chloride, 0.4 mL of triphenyl phosphite (TPP),
0.15 mL of pyridine, and 0.3 mL of NMP was heated with
stirring at 120 8C for 3 h. The resulting solution was poured
with stirring into methanol/H2O. The precipitated product
was washed repeatedly with methanol and hot water, and
dried to give a quantitative yield of model compound M. IR
spectrum of M: 3255 (amide N2H stretch), 1648 cm21
(amide carbonyl stretch). 1H NMR (600 MHz, DMSO-d6, d,
ppm): 10.20 (s, 2H, amide protons), 7.94 (d, J 5 7.4 Hz, 4H,
Hh), 7.69 (d, J 5 8.6 Hz, 4H, Hg), 7.63 (d, J 5 8.8 Hz, 2H, Ha),
7.57 (t, J 5 7.1 Hz, 2H, Hj), 7.51 (t, J 5 7.4 Hz, 4H, Hi), 7.04
(d, J 5 8.7 Hz, 4H, Hd), 7.00 (d, J 5 8.6 Hz, 4H, Hf), 6.96 (d,
1H NMR (600 MHz, DMSO-d6, d, ppm) (Codes of the hydro-
gen atoms: see Fig. 1): 7.94 (s, 2H, 2NH2), 7.52 (d, J 5 8.4
Hz, 2H, Ha), 7.14 (d, J 5 8.4 Hz, 4H, Hd), 6.99 (d, J 5 1.8 Hz,
2H, Hc), 6.89 2 6.92 (m, 6H, Hb 1 He), 3.72 (s, 6H, 2OCH3).
N,N’-Bis(4-Methoxyphenyl)-N,N’-Bis(4-Nitrophenyl)-2,7-
Naphthalenediamine (2)
In a 50-mL round-bottom flask equipped with a stirring bar,
a mixture of 7.4 g (0.02 mol) of N,N’-bis(4-methoxyphenyl)-
2,7-naphthalenediamine (1), 6.4 g (0.045 mol) of p-fluoroni-
trobenzene, and 6.8 g (0.045 mol) of cesium fluoride (CsF)
in 35 mL of dimethyl sulfoxide (DMSO) was heated at 140 8C
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JOURNAL OF POLYMER SCIENCE, PART A: POLYMER CHEMISTRY 2017, 00, 000–000
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