Masayuki Wakioka, et al. Macromolecules, 2013, 46(2), 370-374.
1,2,4,5-tetrafluorobenzene can be directly arylated with 2,7-dibromo-9,9-dioctylfluorene to prepare π-conjugated polymer PDOF-TP (Mn up to 347700), which can be used in optoelectronic devices. This work proposes an efficient catalytic system combining catalyst precursors Pd2(dba)3·CHCl3 and P(C6H4-o-OMe)3(L1) with carboxylic acid (AcOH or PivOH) and base (Cs2CO3).
Synthesis of PDOF-TP from 1,2,4,5-tetrafluorobenzene
· In a 10 mL Schlenk tube with a Teflon stopcock, 2,7-dibromo-9,9-dioctylfluorene (274 mg, 0.50 mmol), 1,2,4,5-tetrafluorobenzene (75.0 mg, 0.50 mmol), Cs2CO3 (489 mg, 1.5 mmol), AcOH (30.0 mg, 0.50 mmol), Pd2(dba)3·CHCl3 (2.6 mg, 2.5 μmol), L1 (3.5 mg, 10 μmol), and THF (1 mL) were combined.
· The mixture was stirred at room temperature for 0.5 hours followed by heating at 100 °C for 24 hours. After cooling to room temperature, CHCl3 (30 mL) was added to dissolve the polymer, followed by washing with water (10 mL × 2).
· Adding 5 M HCl (10 mL) to the solution and pouring it into vigorously stirred MeOH (100 mL) resulted in a white precipitate of PDOF-TP, which was collected using a membrane filter (0.5 μm). The precipitate was washed with MeOH and dried under vacuum at room temperature overnight. Purification was done by Soxhlet extraction with CHCl3, yielding a white solid of PDOF-TP (236 mg, 87% yield, Mn = 132,800, Mw/Mn = 2.61).
