9132 Choi et al.
Macromolecules, Vol. 38, No. 22, 2005
RCH2-OR), 2.39 (s, 3H, Ar-CH ), 1.0-1.7 (m, 13H, aliphatic
H + remaining reactant), 0.80 (t, 3H, R-CH3 + remaining
reactant).
amine in 10 mL of DMF was added. The reacting mixture was
stirred for 24 h at room temperature under a nitrogen
atmosphere; afterward, the mixture was concentrated in a
vacuum to 5 mL. The polymer was precipitated by pouring
the solution into 100 mL of methanol. After centrifugation,
the solvent was decanted, and the product was washed several
times with methanol and dried. The reaction yielded 340 mg
of a pale yellow solid.
(()-4′-(1-Methylheptyloxy)biphenyl-4-ol (2). A solution of 16.9
g (0.3 mol) of potassium hydroxide and 57.6 g (0.3 mol) of 4,4′-
dihydroxybiphenyl in 750 mL of methanol was heated to reflux
under a nitrogen atmosphere. After that, a solution of 95.6 g
(0.3 mol) of (()-4-toluenesulfonic acid-2-octyl ester prepared
according to ref 37 in 160 mL of methanol was added in small
portions during 8 h. The reaction mixture was then refluxed
for another 40 h, and the solvent was removed in a vacuum.
The residue was stirred for 1 h with 2 N hydrochloric acid,
filtered, and washed twice with water and once with a small
amount of ethanol. The crude product was purified by column
chromatography (petrol ether/ethyl acetate 8:1). The reaction
yielded 25.3 g (0.084 mol, 28%) of colorless solid (mp: 76 °C).
1H NMR (CDCl3, 200 MHz): δ ) 7.41 (m, 4H, arom H, meta
to O), 6.88 (m, 4H, arom H, ortho to O), 4.36 (m, 1H, RCH2O-
R), 3.32 (bs, 1 H, OH), 1.1-1.8 (m, 13H, aliphatic H), 0.87 (t,
3H, CH3).
1H NMR (CDCl3, 200 MHz): δ ) 7.45 (4H, arom H, meta to
O), 6.92 (4H, ortho to O), 4.27 (1H, O-CH), 3.99 (2H, NH-
R-CH2), 3.25 (2H, NH-CH2), 1.31-1.24 (12H, aliphatic H +
main chain), 0.86 (3H, O-R-CH3).
LC Ionomers P2. A sample of 501 mg (2.96 mmol repeating
units) of poly(N-acryloyloxysuccinimide) was dissolved in 40
mL of DMF and heated to 50 °C. Subsequently, a solution of
587 mg (1.48 mmol repeating units) of primary amine in 10
mL of DMF was added for P2. The reacting mixture was
stirred for 5 h at RT under a nitrogen atmosphere. It was
checked by thin-layer chromatography that no free amine was
left after this time. For P2, a solution of 454 mg (2.96 mmol)
of the 4-aminobutyric acid methyl ester hydrochloride in 10
mL of DMF was then supplemented, and then 4 mL of
triethylamine was added. The mixture was stirred for a further
24 h at 50 °C. Afterward, the mixture was concentrated in a
vacuum to 10 mL. The polymer was precipitated by pouring
the solution into 100 mL of methanol. After centrifugation,
the solvent was decanted, and the product was washed several
times with methanol and dried. The reaction yielded P2 as
bright-yellow solids.
13C NMR (CDCl3, 50.3 MHz): δ ) 157.4 (1C, arom C, ipso
to -OR), 154.6 (1C, arom C, ipso to OH), 133.8 and 133.2 (2C,
arom C, para to O), 127.9 and 127.7 (4C, arom C, meta to O),
116.2 and 115.6 (4C, arom C, ortho to O), 68.5 (1C, RCH2O),
36.5, 31.8, 29.3, 25.6, 22.6, 19.8, 14.1 (7C, aliphatic C).
(()-N-{6-[4′-(1-Methylheptyloxy)biphenyl-4-yloxy]hexyl}-
phthalimide (3). A mixture of N-(6-bromohexyl)phthalimide
(14.05 g, 45 mmol), (()-4′-(1-methylheptyloxy)biphenyl-4-ol
(13.57 g, 45 mmol), potassium hydroxide (2.7 g, 48 mmol), and
a catalytic amount of KI in 100 mL of methanol was heated to
reflux for 4 days under a nitrogen atmosphere. After cooling
to 4 °C, a white solid precipitated which was isolated and
washed with a small amount of cool methanol. The product
yielded 10.3 g (19.5 mmol, 43%) of a white solid (mp: 64 °C).
1H NMR (DMSO-d6/200 MHz): δ ) 7.83 (m, 4H, arom H of
phthalimide), 7.46 (d, 4H, arom H, meta to O of biphenyl), 6.91
(d, 4H, arom H, ortho to O), 4.41 (m, 1H, O-CH), 3.92 (t, 2H,
O-CH2), 3.56 (t, 2H, N-CH2), 1.1-1.8 (m, 21H, H-6-H-9,
H-19, R-CH2), 0.81 (t, 3H, R-CH3).
1H NMR (CDCl3, 200 MHz): δ ) 7.41 (4H, arom H, meta to
O), 6.87 (4H, ortho to O), 4.31 (1H, O-CH), 3.89 (2H, O-CH2),
3.61 (3H, COOCH3), 3.21 (4H, NH-CH2), 2.31 (2H, CH2-CH2-
COOCH3), 1.71-1.23 (15H, aliphatic H + main chain), 0.86
(3H, O-R-CH3).
IR (ATR): 2927, 2853 (C-H aliphatic), 1737 (COO-CH3),
1644 (CO- NHR), 1497, 1238, 1173, 1035, 822 cm-1
.
Cleavage of the Ester Bond To Obtain LC Ionomer P2. A
solution of 200 mg of the precursor of P2 in 15 mL of DMF
was heated to 40 °C under a nitrogen atmosphere. After that
a solution of 1.1 g of potassium hydroxide in 5.5 mL of water
was added to the reaction mixture with a syringe. The mixture
was stirred for 5 h at 40 °C. As a white product had formed,
the solvent was evaporated, and the residue was washed three
times with 100 mL of water. The mixture was then centrifuged,
and the solvent was decanted. The crude product was added
to the solution of K2CO3 (pH ) 9) and then again centrifuged,
and the solvent was decanted. After drying, 229 mg (9.6 mmol
repeating units, 72%) of a pink solid was obtained.
13C NMR (DMSO-d6, 50.3 MHz): δ ) 167.9 (2C, carbonyl),
157.6 + 156.8 (2C, arom C, ipso to O), 134.3 (2C, arom C of
phthalimide), 132.1 +132.0 (2C, arom C, para to O), 131.5 (2C,
arom C of phthalimide), 127.1 + 127.0 (4C, arom C, meta to
O), 122.9 (2C, arom C of phthalimide), 115.8 + 114.7 (2C, arom
C, ortho to O), 72.9 (1C, O-CH), 67.3 (1C, O-CH2), 37.3 (1C,
N-CH2), 35.8 (1C, O-CH-CH2), 31.2 + 28.6 + 28.4 + 27.7 +
25.9 + 25.1 + 24.8 + 21.9 (8C, aliphatic C), 19.5 (1C, OCH-
CH3), 13.8 (1C, R-CH3).
(()-6-[4′-(1-Methylheptyloxy)biphenyl-4-yloxy]hexylamine (4).
Hydrazine hydrate (1.03 g, 20.6 mmol) was added to a solution
of (()-N-{6-[4′-(1-methylheptyloxy)biphenyl-4-yloxy]hexyl}-
phthalimide (10.2 g, 19.2 mmol) in 100 mL of ethanol. The
mixture was kept under reflux for 16 h. After addition of 10
mL of concentrated HCl, the resulting solution was kept under
reflux for 1 h. After cooling to 4 °C a white solid precipitated
which was isolated. The solid was stirred for 30 min in 1 M
aqueous NaOH. After filtration, the crude product was heated
with 200 mL of CHCl3 and 5 g of Na2SO4 under reflux for 2 h.
Filtration after cooling and evaporation of the organic solvent,
the reaction yielded 4.53 g (11.3 mmol, 60%) of a white product.
1H NMR (CDCl3/200 MHz): δ ) 7.43 (m, 4H, arom H, meta
to O), 6.91 (m, 4H, arom H, ortho to O), 4.35 (m, 1H, O-CH),
3.96 (t, 2H, O-CH2), 2.71 (t, 2H, NH2-CH2), 1.2-2.2 (m + bs,
23H, aliphatic H, NH2), 0.87 (t, 3H, R-CH3).
IR (ATR): 2928, 2856 (C-H aliphatic), 1642 (CO- NHR),
1564, 1497, 1397, 1239, 821 cm-1
.
P3 LC Ionomer. For the synthesis of P3a with 20% of ionic
amines or P3b with 50% of ionic amines, 251.9 mg (1.487 mmol
repeating units) of poly(N-acryloyloxysuccinimide) was dis-
solved in 15 mL of DMF and heated to 50 °C. Subsequently, a
solution of 473.6 mg (1.191 mmol repeating units) of primary
amine for P3a or 295.6 mg (0.744 mmol repeating units) of
primary amine for P3b in 10 mL of DMF was added. The
mixture was stirred for 5 h at 70 °C and then cooled to 50 °C.
After that, a solution of 239 mg (0.912 mmol) of 4-aminobu-
tyltriethylphosphonium chloride hydrochloride in 10 mL of
methanol and 4 mL of triethylamine for P3a or 194 mg (0.744
mmol) of 4-aminobutyltriethylphosphonium chloride hydro-
chloride in 8 mL of methanol and 4 mL of triethylamine for
P3b was added. The mixture was stirred for another 24 h at
50 °C. Afterward, the mixture was concentrated in a vacuum
to 10 mL. The polymer was precipitated by pouring the
solution into 100 mL of diethyl ether. After centrifugation, the
solvent was decanted, and the product was washed several
times with diethyl ether and dried. The reaction yielded P3a
or P3b.
Poly(N-acryloyloxysuccinimide) was prepared as described
in ref 37.
1H NMR (DMSO-d6, 200 MHz): δ ) 3.11 (1H, CH, main
chain), 2.80 (4H, CH2, side groups), 2.08 (2H, CH2, main chain).
13C NMR (DMSO-d6, 50.3 MHz): δ ) 169.8 (2C, RC(O)N),
162.3 (1C, RC(O)O), 35.7 (1C, CH, main chain), 30.7 (1C, CH2,
main chain), 25.4 (2C, CH2, side chain).
Polyelectrolytes. Branched poly(ethylenimine) (PEI) was
purchased from Aldrich and used without further purification.
The synthesis of poly(2-acryloylamino-2-methylpropyl sul-
fonate sodium salt) (PAMPS) and poly(choline methacrylate)
(PCM) were already described elsewhere.36
LC Homopolymer P1. A sample of 255 mg (1.51 mmol
repeating units) of poly(N-acryloyloxysuccinimide) was dis-
solved in 40 mL of DMF and heated to 50 °C. Subsequently, a
solution of 720 mg (1.81 mmol repeating units) of primary