ACCEPTED MANUSCRIPT
o-diaminobenzene (5.4 g, 50 mmol) in DMF (30 mL) was added and the reaction mixture was
then stirred at 120 for 3 h. After cooling down to room temperature, the reaction mixture was
poured into 300 mL water and the precipitate was obtained by filtering. The pure product was
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obtained by recrystallization in ethanol, faint yellow solid, 9.42 g,yield 89.7%. H NMR (400
MHz, DMSO-d6) δppm: 12.63 (s, 1H,), 9.99 (s, 1H), 8.02-8.00 (t, 2H, J = 7.0), 7.55-7.53 (dd, 2H,
J = 3.0, 5.6 Hz), 7.18-7.14 (m, 2H), 6.94-6.91 (t, 2H, J = 6.5).
2.2.3 Synthesis of compound 3 and 4
Compound 3 and 4 were synthesized by the following procedure.
For compound 3: Compound 1 (2.0 g, 5 mmol), carbon tetrabromide (2.7 g, 8 mmol) and
triphenylphosphine (2.1 g, 8 mmol) were dissolved in purified CH2Cl2 (30 mL) and stirred for 24
h at room temperature. The reaction mixture was poured into 50 mL water and the product was
extracted with CH2Cl2 (30 mL×3). The organic phase was dried with anhydrous sodium sulfate,
the purified compound 3 was obtained by column chromatography on silica gel (eluent: petroleum
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ether: CH2Cl2 = 3:1) to give white powder, 1.91 g, yield 83.6%. H NMR (CDCl3, 500MHz) δ
ppm: 7.88-7.86 (d, 1H, J=11.5 Hz), 7.54-7.52 (d, 1H, J=9.0 Hz), 7.48-7.46 (d, 4H, J=9.0 Hz),
7.33-7.15 (m, 9H), 7.04-7.03 (d, 1H, J=3.0 Hz), 6.29-6.26 (d, 1H, J=10.0 Hz), 4.41-4.32 (t, 2H,
J=7.5 Hz), 3.68-3.63 (m, 2H, J=7.5 Hz).
For compound 4: White powder, yield 87.2%. 1H NMR (CDCl3, 500MHz) δ ppm: 7.86-7.84 (d,
1H, J=9.0 Hz), 7.54-7.51 (d, 1H, J=9.0 Hz), 7.49-7.47 (d, 4H, J=9.0 Hz), 7.32-7.12 (m, 9H),
7.01-7.03 (d, 1H, J=2.0 Hz), 6.28-6.25 (t, 1H, J=10.0 Hz), 4.0-4.01 (t, 2H, J=7.0 Hz), 3.45-3.41 (t,
2H, J=7.0 Hz), 1.91-1.82 (m, 4H), 1.56-1.52 (m, 4H).
2.2.4 Synthesis of C2NP-PBI and C6NP-PBI
Compound C2NP-PBI and C6NP-PBI were synthesized by the following procedure.
A mixture of PBI (0.63 g, 3 mmol), anhydrous K2CO3 (0.6 g, 4.5 mmol) and a pinch of KI in
DMF (50 mL) was stirred at room temperature for 1 h, then compound 3 (1.4 g, 3 mmol) was
added into the above reaction mixture. The reaction mixture was heated to 80 ℃ and kept for 24 h.
After cooling down to room temperature, the reaction mixture was poured into 200 mL water. The
precipitate was obtained by filtering and dissolved with ethyl acetate. The organic phase was dried
with anhydrous sodium sulfate, the purified C2NP- PBI was obtained by column chromatography
on silica gel (eluent: petroleum ether: ethyl acetate = 9:2) to give white powder, 1.31 g, yield