Synthesis and optical properties of poly(2,7-(9,9-dihexylfluorene)-3,3′(4,4′-dialkoxybiphenyl))

Figures & data

Figure 1. ¹H NMR spectrum of D4 in CDCl₃ using TMS as internal standard.

Figure 2. ¹³C NMR spectrum of D4 in CDCl₃ using TMS as internal standard.

Figure 3. ¹H NMR spectrum of M4 in CDCl₃ using TMS as internal standard.

Figure 4. ¹³C NMR spectrum of M4 in CDCl₃ using TMS as internal standard.

Figure 5. ¹³C NMR spectrum of M1 in CDCl₃ using TMS as internal standard.

Figure 6. ¹H NMR spectrum of P1 in CDCl₃ using TMS as internal standard.

Figure 7. FT-IR spectrum of P2 in KBr pellet.

Figure 8. Thermograms of (A) P1 and (B) P4 at a heating rate of 20 °C/m.

Figure 9. Optical absorption spectra of the polymers P1–P5 in THF solution.

Figure 10. Photoluminescence spectra of the polymers P1–P5 in solution in THF.

Figure 11. Optical absorption spectra of pristine films of the polymers P1–P5 on quartz plate.

Figure 12. Photoluminescence spectra of pristine films of the polymers P1–P5.

Figure 13. Optical absorption and photoluminescence spectra of pristine and annealed thin films at 50 and 70 °C of the synthesized polymers (A) P1 and (B) P4.

Figure 14. Photoluminescence spectra of pristine and annealed thin films of the synthesized polymers P1–P5.

Figure 15. (A) Electroluminescence spectra of P5 using a single-layer cell with PEDOT:PSS-coated ITO anode and aluminum cathode and (B) the I–V characteristics of the PLED device.

Scheme 1. Synthesis of functional monomers M1–M5.

Scheme 2. Synthesis of polymers P1–P5.

Table 1. Physical results of the synthesized polymers.

Polymer	Mw^a	Mw/Mn	Tg^b (°C)
P1	10,150	1.60	60.5
P2	15,600	2.07	66.5
P3	8800	1.60	74.0
P4	4600	1.38	79.2
P5	12,700	1.73	89.2

^a Determined by GPC based on polystyrene standards using THF as an eluent.

^b Performed under a nitrogen atmosphere at a heating rate of 20 °C/min.

Table 2. Optical properties of the synthesized polymers.

Polymer	Absorbance λmax^a (nm)	Photo luminescence λmax^b (nm)	Absorbance λmax^c (nm)	Photo luminescence λmax^d (nm)	φf^e
P1	330	391 (372,415,440)	336	398 (419)	0.778
P2	327	390 (372,415)	332	393 (416)	0.768
P3	327	387 (372,415)	328	393 (412)	0.764
P4	326	389 (372,410)	326	393 (414)	0.737
P5	326	389 (372,410)	328	393 (416)	0.746

^a Maximum wavelength of absorption in THF.

^b Maximum wavelength of Photoluminescence in THF with shoulder peaks.

^c Maximum wavelength of absorption in polymer film coated on quartz plate.

^d Maximum wavelength of Photoluminescence in polymer film coated on quartz plate.

^e Photoluminescence quantum efficiency with quinine sulfate as standard.