Synthesis of luminescent polyurethane with π-conjugated segment in main chain

The synthesis of luminescent polyurethane with π-conjugated segment in main chain, was investigated. To a mixture of 2,7-Dibromofluorene (3.9 g, 12 mmol) (compound 1) and catalytic amounts of triethyl benzylammonium chloride in a 100 ml Schlenk tube was added DMSO (18 mL) under nitrogen. After half an hour, 1-bromo-dodecane was added to the reacting mixture, and then the mixture was treated with 5.5 mL of 59 % aqueous NaOH at 60 ° Celsius stirred for 12 hour. After cooling the mixture to room temperature, ether (500 mL) was added. The organic layer was washed with 100 mL of a 1.0 M hydrochloric acid solution and 150 mL of water. The organic layer was dried by MgSO₄ and concentrated under reduced pressure. The oily residue was purified by flash column chromatography. These functionalized general PU could be further made into coatings, fibers, and plastics with various applications.