Recognition of Macromolecular Sequence Information
A R T I C L E S
in dry DMAc (30 mL) under nitrogen for 16 h. The clear, pale yellow
solution was concentrated to ca. 5 mL and cooled to room temperature.
The yellow crystals were filtered off, washed with DMAc (2 mL) and
methanol (10 mL), and dried at 100 °C for 2 h to afford 9 as a crystalline
yellow solid.
dride (0.218 g, 1 mmol) was added in one portion. The dianhydride
gradually dissolved and the mixture became viscous after 0.5 h. The
pale yellow viscous solution was stirred for a further 20 h, then
transferred to a Petri dish and heated at 80 °C under vacuum for 2 h to
remove the solvent. The resulting film of polyamic acid was imidized
by heating sequentially at 120 °C for 10 min, 150 °C for 10 min, 180
°C for 10 min, 210 °C for 10 min, and finally at 250 °C for 30 min.
The polyimide film was dissolved in DMF and reprecipitated twice in
methanol to give uniform beads of polyimide 14 which were dried at
80 °C for 4 h.
Diimide 5. Yield 0.6 g, 54%; mp 356 °C. 1H NMR (CDCl3/
hexafluoropropan-2-ol 6:1 v/v, 250 MHz) δ 8.46 (s, 2H), 7.93 (d, J )
8.6 Hz, 4H), 7.89 (d, J ) 8.9 Hz, 4H), 7.75 (d, J ) 8.6 Hz, 4H), 7.61
(t, J ) 8.1 Hz, 2H), 7.58 (d, J ) 8.6 Hz, 4H), 7.51 - 7.44 (m), 7.30
(dd, J ) 8.1 and 2.1 Hz, 2H), 7.20 (dd, J ) 8.1 and 2.1 Hz, 2H),
7.17(d, J ) 8.9 Hz, 4H), 7.16 (t, J ) 2.1 Hz, 2H). 13C NMR (CDCl3/
hexafluoropropan-2-ol 6:1 v/v, 62.5 MHz) δ 165.7, 162.2, 156.0, 147.5,
139.2, 138.8, 137.4, 134.6, 132.1, 131.5, 130.2, 129.5, 129.2, 128.6,
128.1, 127.7, 123.2, 121.3, 120.1, 118.9, 118.7. IR (Nujol): 1723 (imide
νCdO), 1375 (νC-N), 1243 (νC-O-C), 1160, 901, 848 and 835
cm-1. MS (MALTI-TOF): m/z ) 1007 [M + Na]+. Anal. Calcd for
C58H36N2O10S2: C, 70.72; H, 3.68; N, 2.84%. Found: C, 70.72; H,
3.59; N, 2.94%.
Diimide 7. Yield 1.01 g, 85%; mp 398 °C. 1H NMR (CDCl3/
hexafluoropropan-2-ol 6:1 v/v, 700 MHz) δ 8.51 (s, 2H), 7.49 (t, J )
7.7 Hz, 2H), 7.45 (d, J ) 7.7 Hz, 2H), 7.40 (t, J ) 7.7 Hz, 2H), 7.23
(d, J ) 7.7 Hz, 1H), 7.21 (d, J ) 7.7 Hz, 1H), 2.21 (s), 2.20 (s). 13C
NMR (CDCl3/hexafluoropropan-2-ol 6:1 v/v, 62.5 MHz) δ 166.4, 137.7,
136.8, 132.0, 131.0, 129.4, 128.6, 127.8, 120.2, 17.7. IR (Nujol): 1729
(imide νCdO), 1371 (νC-N), 757 and 726 cm-1. MS (CI): m/z )
396 [M]+. Anal. Calcd for C24H16N2O4: C, 72.72; H, 4.07; N, 7.07%.
Found: C, 72.70; H, 4.02; N, 7.16%.
Diimide 9. Yield 1.12 g, 74%; mp 326 °C. 1H NMR (CDCl3/
hexafluoropropan-2-ol 6:1 v/v, 700 MHz) δ 8.53 (s, 2H), 7.79 (d, J )
7.9 Hz, 2H), 7.76 (s, 2H), 7.72 (t, J ) 7.9 Hz, 2H), 7.67 (d, J ) 7.9
Hz, 2H). 13C NMR (CDCl3/hexafluoropropan-2-ol 6:1 v/v, 62.5 MHz)
δ 165.7, 137.4, 132.9, 132.4, 131.2, 130.6, 130.0, 126.4, 124.0, 120.3.
IR (Nujol): 1713 (imide νCdO), 1391 (νC-N), 900, 840, and 797
cm-1. MS (CI): m/z ) 504 [M]+. Anal. Calcd. for C24H10F6N2O4: C,
57.16; H, 2.00; N, 5.55%. Found: C, 57.08; H, 1.99; N, 5.55%.
Diimide 10. Yield 1.0 g, 60%; mp 344 °C. 1H NMR (CDCl3/
hexafluoropropan-2-ol 6:1 v/v, 250 MHz) δ 8.87 (s, 2H), 7.86 (d, J )
7.9 Hz, 2H), 7.76 (t, J ) 7.9 Hz, 2H), 7.63 (s, 2H), 7.54 (d, J ) 7.9
Hz, 2H). 13C NMR (CDCl3/hexafluoropropan-2-ol 6:1 v/v, 62.5 MHz)
δ 163.9, 134.6, 133.3, 132.8, 132.6, 132.1, 130.9, 127.5, 127.1, 125.9,
125.8, 121.5. IR (Nujol): 1712 (imide νCdO), 1378 (νC-N), 1160,
775, and 742 cm-1. MS (CI): m/z ) 554 [M]+. Anal. Calcd for
C28H12F6N2O4: C, 60.66; H, 2.18; N, 5.05%. Found: C, 60.44; H, 2.10;
N, 4.97%.
Unsymmetrical Diimide 8. A mixture of pyromellitic dianhydride
(3.27 g, 15 mmol) and o-toluidine (1.61 g, 15 mmol) in dry DMAc
(200 mL) was stirred at room temperature under nitrogen for 0.5 h.
Then 3-(trifluoromethyl)aniline (2.90 g, 18 mmol) was added. The
reaction mixture was heated for 16 h, cooled, precipitated in water,
filtered, dried at 100 °C for 2 h, and purified by chromatography
(dichloromethane/hexane 1:1) followed by four crystallizations from
chloroform. Yield 0.48 g, 7.0%; mp 267 °C. 1H NMR (CDCl3/
hexafluoropropan-2-ol 6:1 v/v, 700 MHz) δ 8.52 (s, 2H), 7.78 (d, J )
7.9 Hz, 1H), 7.76 (s, 1H), 7.72 (t, J ) 7.9 Hz, 1H), 7.67 (d, J ) 7.9
Hz, 1H), 7.49 (t, J ) 7.7 Hz, 1H), 7.45 (d, J ) 7.7 Hz, 1H), 7.41 (t,
J ) 7.7 Hz, 1H), 7.23 (d, J ) 7.7 Hz, 1H), 7.21 (d, J ) 7.7 Hz, 1H),
2.20 (d, J ) 7.8 Hz, 3H). 13C NMR (CDCl3/hexafluoropropan-2-ol 6:1
v/v, 62.5 MHz) δ 165.6, 137.4, 132.9, 132.4, 131.2, 130.6, 130.0, 126.4,
120.3, 17.7. IR (Nujol): 1719 (imide, νCdO), 1377 (νC-N), 900, 837,
and 766 cm-1. MS (CI): m/z ) 450 [M]+. Anal. Calcd for
C24H13F3N2O4: C, 64.00; H, 2.91; N, 6.22%. Found: C, 63.74; H, 2.73;
N, 6.18%.
Polyimide 14. Yield, 0.81 g, 96%; Tg ) 313 °C, ηinh ) 0.66 dL
1
g-1; Mn ) 54000, Mw ) 87000. H NMR (CDCl3/hexafluoropropan-
2-ol 6:1 v/v, 700 MHz) δ 8.52 (s), 8.48 (s), 8.45 (s), 7.99-7.96 (m),
7.89 (br), 7.73-7.70 (m), 7.60-7.57 (m), 7.32 (br), 7.23-7.21 (m),
7.17 (br), 7.10 (br), 7.06 (br), 2.36 (s). 13C NMR (CDCl3/hexafluoro-
propan-2-ol 6:1 v/v, 62.5 MHz) δ 166.2, 165.6, 162.3, 156.7, 155.8,
144.8, 141.0, 139.5, 137.6, 137.4, 134.4, 132.4, 131.5, 130.6, 130.4,
128.5, 128.4, 126.1, 123.3, 123.1, 119.1, 118.8, 18.1. IR (film from
DMF): 1779, 1729 (imide νCdO), 1375 (νC-N), 1246 (νC-O-C),
1107, 728 cm-1
.
Polyimide 16. Yield, 0.28 g, 88%; Tg ) 308 °C, ηinh ) 0.61 dL
1
g-1; Mn ) 46000, Mw ) 67000. H NMR (CDCl3/hexafluoropropan-
2-ol 6:1 v/v, 700 MHz) δ 8.51 (s), 8.48 (s), 8.45 (s), 7.97 (br), 7.90 (d,
J ) 8.2 Hz), 7.72 (d, J ) 8.0 Hz), 7.60-7.57 (m), 7.32 (br), 7.24-
7.21 (m), 7.17-7.16 (m), 7.10 (br), 7.04 (br), 2.36 (s). 13C NMR
(CDCl3/hexafluoropropan-2-ol 6:1 v/v, 62.5 MHz) δ 166.2, 165.7,
162.4, 156.7, 155.8, 144.8, 140.9, 139.5, 137.6, 137.4, 134.4, 132.3,
131.5, 130.6, 130.4, 128.5, 128.4, 126.1, 123.3, 123.1, 119.1, 118.8,
18.1. IR (film from DMF): 1779, 1729 (imide νCdO), 1375 (νC-N),
1246 (νC-O-C), 1107, 728 cm-1
.
Copolyimide 19. Yield, 90%, Tg ) 273 °C, ηinh ) 0.74 dL g-1; Mn
) 68.4 × 103 daltons; Mw ) 109 × 103 daltons (polystyrene standards).
1H NMR (CDCl3/hexafluoro-propan-2-ol 6:1 v/v, 700 MHz): δ ) 8.44
(s), 8.06 (s), 8.01 (d, J ) 8.0 Hz), 7.95 (m), 7.88 (m), 7.70 (br), 7.57
(m), 7.31 (d, J ) 7.9 Hz), 7.23 (d, J ) 8.0 Hz), 7.16 (m), 7.07 (s)
ppm. 13C NMR (CDCl3/hexafluoro-propan-2-ol 6:1 v/v, 62.5 MHz):
δ ) 167.3, 167.1, 165.7, 162.3, 155.9, 144.8, 140.8, 140.2, 137.4, 137.0,
134.3, 134.2, 132.5, 132.4, 132.3, 132.1, 130.4, 128.9, 126.0, 124.9,
123.5, 123.3, 121.2, 121.0, 120.0, 118.9 ppm. IR (film from DMF):
1779, 1729 (imide, νCdO), 1375 (νC-N), 1249 (νC-O-C), 1106,
725 cm-1
.
Copolyimide 20. Yield, 86%, Tg ) 276 °C, ηinh ) 0.41 dL g-1; Mn
) 9.3 × 103 daltons; Mw ) 23.2 × 103 daltons (poly(ethylene glycol).
1H NMR (CDCl3/hexafluoro-propan-2-ol, 6:1 v/v, 250 MHz) δ ) 8.45
(s), 7.95 (m), 7.71 (d, J ) 8.0 Hz), 7.57 (m), 7.32 (d, J ) 8.4 Hz),
7.24 (d, J ) 8.2 Hz), 7.17 (m), 7.09 (br) ppm. 13C NMR (CDCl3/
hexafluoro-propan-2-ol 6:1 v/v, 62.5 MHz): δ ) 167.4, 167.2, 165.7,
162.4, 155.9, 144.9, 140.8, 140.2, 137.4, 137.0, 134.2, 132.4, 132.2,
132.1, 131.5, 130.4, 128.9, 128.5, 128.4, 128.3, 125.9, 124.9, 123.5,
123.4, 121.3, 120.0, 118.9 ppm. IR (film from DMF): 1779, 1728
(imide, νCdO), 1373 (νC-N), 1246 (νC-O-C), 1107, 725 cm-1
.
X-ray Crystallography. Single crystals of complex 6 were grown
by vapor diffusion of an equimolar solution of the two components in
chloroform/hexafluoropropan-2-ol (6/1 v/v) with diethyl ether as
nonsolvent. Crystal data for 6: C87H53Cl2N5O12S2‚3C3H2F6O‚CHCl3 Mr
) 2118.9, triclinic, P1h, a ) 10.9503(4), b ) 17.6840(10), c ) 23.9264-
(12) Å, R ) 104.520(2), â ) 96.031(3), γ ) 91.682(3)°. V ) 4452.9-
(4) Å,3 T ) 120(2) K, Z ) 2, Dc ) 1.58 g cm-3, µ (Mo KR) ) 0.32
mm-1, F (000) ) 2152. Independent measured reflections 9168. R1 )
0.139, wR2 ) 0.391 for 6742 independent observed reflections [2θ e
20.8°, I > 2σ(I)]. Average I/σ(I) 15.5. CCDC 248234. Crystals of 11
were grown by vapor diffusion of an equimolar solution of the two
components in chloroform/hexafluoropropan-2-ol (6/1 v/v) with hexane
as nonsolvent. Crystal data for 11: C70H40F6N4O6‚4C3H2F6O‚H2O Mr
) 1837.3, monoclinic, P21/c, a ) 14.688(17), b ) 25.33(3), c ) 20.85-
(2) Å, â ) 101.701(10)°. V ) 7596(15) Å,3 T ) 150(2) K, Z ) 4, Dc
Synthesis of Polyimides. The synthesis of polyimide 14 is given as
an example. Diamines 12 (0.324 g, 0.5 mmol) and 13 (0.338 g, 0.5
mmol) were dissolved in DMAc (4 mL) by stirring at room temperature,
and when the diamines had dissolved completely pyromellitic dianhy-
9
J. AM. CHEM. SOC. VOL. 129, NO. 51, 2007 16173