Supporting Information
Direct condensation polymerization of N-alkylated p-aminobenzoic
acid and packing of the rigid-rod main chains with flexible side
chains
Yuji SHIBASAKI1†, Yoko ABE,1 Natsuki SATO,2 Atsuhiro FUJIMORI,2 Yoshiyuki OISHI1
1Department
of Chemistry & Bioengineering, Faculty of Engineering, Iwate University, 4-3-5 Ueda,
Morioka, Iwate 020-8551, Japan
2Department
of Polymer Science and Engineering, Faculty of Engineering, Yamagata University, Jonan
4-3-16, Yonezawa,Yamagata 992-8510, Japan
1
Synthesis of p-(N-propylamino)benzoic acid
Into a three-necked flask equipped with a reflux condenser, a thermometer, and a three-way stopcock
was added 4-aminobenzoic acid ethyl ester (79.3 g, 0.480 mol) under nitrogen. HMPA (222 mL) was
then added and the mixture was stirred until the solid was completely dissolved at 20°C. 1-Iodopropane
(42.9 g, 0.252 mol) was then added into this solution, and the mixture was stirred at 130°C for 4 h. The
resultant mixture was poured into water (1 L), and the precipitate was washed with methanol/water (1:5
v/v) mixed solvent to remove the residual solvent and salt. The solid was collected by filtration, purified
by recrystallization from methanol, and dried in vacuo at 80°C for 12 h to give ethyl-p-(Npropyl)aminobenzoate as yellow needles. Yield 46.5 g (88.9%). M.p. 70 - 73°C. IR (KBr):  3373 (NH), 3063 (aromatic C-H), 2964 (aliphatic C-H), 1676 (ester C=O), 1343 (Ar-N), 1173 (C-O) cm-1. 1H
NMR (CDCl3, 400 MHz):  1.00 (t, 3H, CH3), 1.36 (t, 3H, CH3), 1.65 (m, 2H, CH2), 3.13 (t, 2H, CH2),
4.11 (s, 1H, NH), 4.31 (q, 2H, CH2), 6.53 (d, 2H, ArH), 7.86 (d, 2H, ArH) ppm. 13C NMR (CDCl3, 100
MHz):  11.6, 14.5, 22.5, 45.2, 60.1, 111.3, 118.4, 131.5, 152.1, 166.9 ppm. The resulting ethyl p-(Npropylamino)benzoate (38.3 g, 0.185 mol) was placed in a 500-mL two-necked flask equipped with a
reflux condenser. Potassium hydroxide (56.8 g, 0.923 mol) and ethanol (450 mL) were added into this
flask, and heated to 90°C. After 7 h, the reaction mixture was poured into water, and the pH of the
solution was adjusted to be around 4 with hydrochloric acid. The precipitate was collected, washed with
water, recrystallized with methanol, and dried in vacuo at 80°C for 12 h to give the title compound as
yellow needles. Yield 21.2 g (64.1%). M.p. 164 -169°C. IR (KBr):  3377 (N-H), 3058 (aromatic C-H),
2961 (aliphatic C-H), 1663 (C=O), 1313 (Ar-N), 1171 (C-O) cm-1. 1H NMR (CDCl3

CH3), 1.66 (q, 2H, CH2), 3.15 (t, 2H, CH2), 6.55 (d, 2H, ArH), 7.91 (d, 2H, ArH).
NMR (CDCl3
13C
 11.5, 22.5, 45.1, 111.3, 117.0, 132.3, 152.7, 172.2 ppm. Anal. Calcd.
for C10H13NO2 : C, 67.02; H, 7.31; N, 7.82%. Found: C, 66.92; H, 7.26; N, 7.88%.
Synthesis of p-(N-butylamino)benzoic acid
2
The title compound was prepared in a manner similar to that described above. The solid was collected
by filtration, purified by recrystallization from methanol, and dried in vacuo at 80°C for 12 h to give
pale-yellow needles. Yield 1.36 g (74.0%). M.p. 149 - 155°C. IR (KBr):  3398 (N-H), 3058 (aromatic
C-H), 2961 (aliphatic C-H), 1662 (C=O), 1316 (Ar-N), 1172 (C-O) cm-1. 1H NMR (CDCl3, 400 MHz):
 0.96 (t, 3H, CH3), 1.45 (m, 2H, CH2), 1.62 (m, 2H, CH2), 3.18 (t, 2H, CH2), 6.54 (d, 2H, ArH), 7.91
(d, 2H, ArH) ppm. 13C NMR (CDCl3
 13.8, 20.2, 31.4, 43.0, 111.3, 117.0, 132.4, 152.8,
172.4 ppm. Anal. Calcd. for C11H15NO2: C, 68.37; H, 7.82; N, 7.25%. Found: C, 68.29; H, 7.81; N,
7.27%.
Synthesis of p-(N-pentylamino)benzoic acid
The title compound was prepared in a manner similar to that described above. The solid was collected
by filtration, purified by recrystallization from methanol, and dried in vacuo at 80 ˚C for 12 h to give
colorless needles. Yield 18.6 g (68.0%). M.p. 132 - 133 ˚C. IR (KBr):  3400 (N-H), 3056 (aromatic CH), 2959 (aliphatic C-H), 1664 (C=O), 1315 (Ar-N), 1172 (C-O) cm-1. 1H NMR (CDCl3, 400 MHz): 
0.97 (m, 3H, CH3), 1.41 (m, 4H, CH2), 1.67 (m, 2H, CH2), 3.20 (t, 2H, CH2), 6.58 (d, 2H, ArH), 7.95 (d,
2H, ArH) ppm. 13C NMR (CDCl3, 100 MHz):  14.0, 22.5, 29.0, 29.2, 43.3, 111.3, 117.0, 132.4, 152.8,
172.4 ppm. Anal. Calcd. for C12H17NO2: C, 69.54; H, 8.27; N, 6.76%. Found: C, 69.57; H, 8.20; N,
6.81%.
Synthesis of p-(N-heptylamino)benzoic acid
The title compound was prepared in a manner similar to that described above. The solid was collected
by filtration, purified by recrystallization from methanol, and dried in vacuo at 80°C for 12 h to give
colorless needles. Yield 11.3 g (75.0%). M.p. 107 - 122°C. IR (KBr):  3424 (N-H), 3067 (aromatic C3
H), 2959 (aliphatic C-H), 1668 (C=O), 1312 (Ar-N), 1173 (C-O) cm-1. 1H NMR (CDCl3, 400 MHz): 
0.91 (t, 3H, CH3), 1.46 (m, 8H, CH2), 1.64 (m, 2H, CH2), 3.17 (t, 2H, CH2), 6.55 (d, 2H, ArH), 7.93 (d,
2H, ArH) ppm.
13C
NMR (CDCl3, 100 MHz):  14.1, 22.6, 27.0, 29.0, 29.3, 31.8, 43.3, 111.3, 117.0,
132.3, 152.8, 172.4 ppm. Anal. Calcd. for C14H21NO2: C, 71.46; H, 8.99; N, 5.95%. Found: C, 71.33; H,
8.93; N, 6.09%.
Synthesis of p-(N-octylamino)benzoic acid
The title compound was prepared in a manner similar to that described above. The solid was collected
by filtration, purified by recrystallization from methanol, and dried in vacuo at 80°C for 12 h to give
yellow needles. Yield 13.6 g (84.0%). M.p. 117 - 125°C. IR (KBr):  3416 (N-H), 3065 (aromatic C-H),
2960 (aliphatic C-H), 1671 (C=O), 1312 (Ar-N), 1172 (C-O) cm-1. 1H NMR (CDCl3, 400 MHz):  0.91
(t, 3H, CH3), 1.37 (m, 10H, CH2), 1.66 (m, 2H, CH2), 3.20 (t, 2H, CH2), 6.58(d, 2H, ArH), 7.95 (d, 2H,
ArH) ppm. 13C NMR (CDCl3, 100 MHz):  14.1, 22.7, 27.1, 29.2, 29.3, 29.4, 31.8, 43.4, 111.3, 117.0,
132.4, 152.8, 172.3 ppm. Anal. Calcd. for C15H23NO2: C, 72.25; H, 9.30; N, 5.62%. Found: C, 72.28; H,
9.35; N, 5.73%.
Synthesis of p-(N-heptadecylamino)benzoic acid
The title compound was prepared in a manner similar to that described above. The solid was collected
by filtration, purified by recrystallization from methanol, and dried in vacuo at 80°C for 12 h to give
white needles. Yield 9.60 g (64.0%). M.p. 126 -127°C. IR (KBr):  3426 (N-H), 3074 (aromatic C-H),
2954 (aliphatic C-H), 1660 (C=O), 1314 (Ar-N), 1169 (C-O) cm-1. 1H NMR (CDCl3, 400 MHz):  0.88
(t, 3H, CH3), 1.26 (m, 28H, CH2), 1.58 (m, 2H, CH2), 3.06 (q, 2H, CH2), 4.12 (s, 1H, NH), 6.56 (d, 2H,
ArH), 7.67 (d, 2H, ArH), 12.0 (s, 1H, OH) ppm. 13C NMR (CDCl3, 100 MHz):  13.9, 22.1, 26.6, 28.5,
4
28.7, 28.8, 29.0, 29.1, 31.3, 42.3, 110.5, 116.5, 131.0, 152.6, 167.5 ppm. Anal. Calcd. for C24H41NO2:
C, 76.75; H, 11.00; N, 3.73%. Found: C, 76.84; H, 10.87; N, 3.72%.
Synthesis of poly(p-benzamide) (PABA0)
Into a three-necked flask equipped with a reflux condenser, three-way stopcock, and thermometer
were added lithium chloride (10.5 g, 0.247 mol, 4 wt% to the solution), NMP (200 mL), and pyridine
(50 mL). The mixture was stirred until the solid was dissolved. p-Amino benzoic acid (13.7 g, 0.100
mol) was then added into the flask, followed by triphenyl phosphite (31.3 g, 0.100 mol) in one potion.
The flask was heated to 100°C, and the polymerization was kept stirring for another 6 h. The resulting
heterogeneous solution was poured into methanol, and stirred for 5 h. The precipitate was collected,
washed with hot water, and dried in vacuo at 220°C for 24 h to give the title compound. Yield 11.4 g
(95.0%). inh = 1.18 dL/g (0.5 g/dL in sulfuric acid, 30 ˚C). IR (KBr):  3446 (N-H), 1669 (C=O), 1315
(Ar-N), 1177 (amide C-N) cm-1. Anal. Calcd. for (C7H5NO)n: C, 70.58; H, 4.23; N, 11.76%. Found: C,
69.33; H, 4.75; N, 10.96%.
Synthesis of N-methylated poly(p-benzamide) (PABA1)
Into a three-necked flask equipped with a reflux condenser, three-way stopcock, and thermometer
were added p-(N-methylamino)benzoic acid (4.55 g, 30.1 mol), triphenylphosphine (9.44 g, 36.0 mmol),
and pyridine (30 mL). The mixture was stirred until the solid was dissolved. Hexachloroethane (8.52 g,
36.0 mmol) was then added into this solution and the mixture was refluxed for 24 h. After the solution
was cooled to room temperature, it was poured into methanol/hydrogen chloride, and stirred for 5 h. The
precipitate was collected, washed with hot methanol for 12 h, and dried in vacuo at 220°C for 24 h to
give the title compound. Yield 2.22 g (55.6%). inh = 0.61 dL/g (0.5 g/dL in sulfuric acid, 30°C). IR
(KBr):  3051 (N-H), 2923 (aliphatic C-H), 1645 (C=O), 1368 (Ar-N), 1175 (amide C-N) cm-1. Anal.
Calcd. for (C8H7NO)n: C, 72.16; H, 5.30; N, 10.52%. Found: C, 71.49; H, 5.29; N, 10.39%.
5
Synthesis of N-propylated poly(p-benzamide) (PABA3)
The title compound was prepared by a similar method to that described above. Yield 0.743 g (46.1%).
inh = 0.65 dL/g (0.5 g/dL in conc. sulfuric acid, 30°C). IR (KBr):  3051 (N-H), 2963 (aliphatic C-H),
1645 (C=O), 1388 (arom C-N), 1123 (amide C-N) cm-1. Anal. Calcd. for (C10H11NO)n: C, 74.51; H,
6.88; N, 8.69%. Found: C, 74.31; H, 6.84; N, 8.73%.
Synthesis of N-butylated poly(p-benzamide) (PABA4)
The title compound was prepared by a similar method to that described above. Yield 3.29 g (52.1%).
inh = 0.42 dL/g (0.5 g/dL in conc. sulfuric acid, 30°C). IR (KBr):  3048 (N-H), 2958 (aliphatic C-H),
1646 (C=O), 1382 (Ar-N), 1121 (amide C-N) cm-1. Anal. Calcd. for (C11H13NO)n: C, 75.40; H, 7.48; N,
7.99%. Found: C, 75.31; H, 7.44; N, 8.25%.
Synthesis of N-pentylated poly(p-benzamide) (PABA5)
The title compound was prepared by a similar method to that described above. Yield 2.63 g (64.0%).
inh = 0.29 dL/g (0.5 g/dL in conc. sulfuric acid, 30°C). IR (KBr):  3044 (N-H), 2930 (aliphatic C-H),
1645 (C=O), 1388 (Ar-N), 1123 (amide C-N) cm-1. Anal. Calcd. for (C12H15NO)n: C, 76.16; H, 7.99; N,
7.40%. Found: C, 76.03; H, 7.90; N, 7.71%.
Synthesis of N-heptylated poly(p-benzamide) (PABA7)
The title compound was prepared by a similar method to that described above. Yield 3.32 g (62.0%).
inh = 0.15 dL/g (0.5 g/dL in conc. sulfuric acid, 30°C). Mw (LS) = 47,800. IR (KBr):  3055 (N-H),
6
2925 (aliphatic C-H), 1654 (C=O), 1387 (Ar-N), 1124 (amide C-N) cm-1. Anal. Calcd. for (C14H19NO)n:
C, 77.38; H, 8.81; N, 6.45%. Found: C, 77.31; H, 8.81; N, 6.78%.
Synthesis of N-octylated poly(p-benzamide) (PABA8)
The title compound was prepared by a similar method to that described above. Yield 2.34 g (51.0%).
inh = 0.06 dL/g (0.5 g/dL in conc. sulfuric acid, 30 ˚C). Mw (LS) = 20,600. IR (KBr):  3050 (N-H),
2920 (aliphatic C-H), 1655 (C=O), 1360 (Ar-N), 1130 (amide C-N) cm-1. Anal. Calcd. for (C15H21NO)n:
C, 76.16; H, 7.99; N, 7.40%. Found: C, 77.88; H, 9.04; N, 6.17%.
Synthesis of N-heptadecylated poly(p-benzamide) (PABA17)
The title compound was prepared by a similar method described above. Yield 2.34 g (51.0%). inh =
0.34 dL/g (0.5 g/dL in chloroform, 30°C). Mw (LS) = 93,400. IR (KBr):  3058 (N-H), 2921 (aliphatic
C-H), 1653 (C=O), 1386 (Ar-N), 1128 (amide C-N) cm-1. Anal. Calcd. for (C24H39NO)n: C, 80.61; H,
10.99; N, 3.92%. Found: C, 80.67; H, 11.12; N, 4.08%.
7
Caption to Figures
Figure 1S. IR full spectra of PABAn
Figure 2S. WAXD profile of PABA0
Figure 3S. WAXD profile of PABA1
Figure 4S. WAXD profile of PABA3
Figure 5S. WAXD profile of PABA4
Figure 6S. WAXD profile of PABA5
Figure 7S. WAXD profile of PABA7
Figure 8S. WAXD profile of PABA8
Figure 9S. WAXD profile of PABA17
Figure 10S. SAXS profile of PABA5 and PABA17
8
PABA0
PABA1
Transmittance
PABA3
PABA4
PABA5
PABA7
PABA8
PABA17
4000
3000
2000
1000
400
Wavenumbers / cm-1
Figure 1S. Y. Shibasaki et al.
9
Poly(p-benzamide)
350
Intensity / cps
300
250
200
150
100
50
0
4
8
12
16
20
24
28
32
2 / degree
Figure 2S. Y. Shibasaki et al.
10
Poly(p-N-methylbenzamide)
Intensity / cps
240
160
80
0
4
8
12
16
20
24
28
32
2 / degree
Figure 3S. Y. Shibasaki et al.
11
Poly(N-propylbenzamide)
Intensity / cps
800
600
400
200
0
4
8
12
16
20
24
28
32
2 / degree
Figure 4S. Y. Shibasaki et al.
12
Poly(N-butylbenzamide)
250
Intensity / cps
200
150
100
50
0
4
8
12
16
20
24
28
2 / degree
Figure 5S. Y. Shibasaki et al.
13
Poly(N-pentylbenzamide)
500
Intensity / cps
400
300
200
100
0
4
8
12
16
20
24
28
32
2 / degree
Figure 6S. Y. Shibasaki et al.
14
Poly(N-heptylbenzamide)
Intensity / cps
400
300
200
100
4
8
12
16
20
24
28
32
2 / degree
Figure 7S. Y. Shibasaki et al.
15
Poly(N-octylbenzamide)
600
Intensity / cps
500
400
300
200
100
0
4
8
12
16
20
24
28
32
2 / degree
Figure 8S. Y. Shibasaki et al.
16
Poly(N-heptadecylbenzamide)
1000
Intensity / cps
800
600
400
200
0
4
8
12
16
20
24
28
32
2 / degree
Figure 9S. Y. Shibasaki et al.
17
Intensity / cps
1500
PABA17
30.5 Å
1000
500
15.2Å
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
-1
q / nm
Intensity / cps
800
PABA5
600
400
200
0
1
2
3
4
-1
q / nm
Figure 10S. Y. Shibasaki et al.
18