Novel donor-spacer-acceptor compound as the multifunctional component of exciplexes for efficient OLEDs

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Supplementary information

Novel donor-spacer-acceptor compound as the multifunctional component of exciplexes for efficient

OLEDs

Hao-Yu Yang^1,2, Cai-Jun Zheng^1*, Ming Zhang^1,2, Jue-Wen Zhao¹, Yi-Zhong Shi², Chun-Peng Pu¹, Hui Lin¹, Si-Lu Tao¹ and Xiao-Hong Zhang^2*

1School of Optoelectronic Science and Engineering, University of Electronic Science and

Technology of China, Chengdu 610054, P.R. China.

2 Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for

Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu 215123, P.R.

China.

*Corresponding authors (emails: zhengcaijun@uestc.edu.cn (Zheng CJ);

xiaohong_zhang@suda.edu.cn (Zhang XH))

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Synthesis Procedure of 9'-(4-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenoxy)phenyl)-9'H-9,3':6',9''-tercarba zole (3Cz-o-TRz)

2-(4-(4-bromophenoxy)phenyl)-4,6-diphenyl-1,3,5-triazine (TRz-o-PhBr).

4-bromophenol (0.35 g, 2.0 mmol), potassium tert-butoxide (0.67 g, 6.0 mmol) and anhydrous DMF (30 mL) were added to a round-bottom flask (100 mL) under nitrogen atmosphere. The mixture was stirred at 150 °C for 1 h, then TRz-PhBr (0.90 g, 2.3 mmol) was added and stirred at 150 °C for 12 h. After completion of the reaction, water and dichloromethane were added to the cooled mixture. The organic layer was separated, dried over MgSO₄, and concentrated in vacuum. The residue solid was purified by column chromatography to give a white product (0.49 g, 51.04%). ¹H NMR (400 MHz, Chloroform-d) δ 8.76 (d, J = 6.6 Hz, 6H), 7.65 – 7.55 (m, 6H), 7.51 (d, J = 8.8 Hz, 2H), 7.15 (d, J = 8.8 Hz, 2H), 7.00 (d, J = 8.8 Hz, 2H).

9'-(tert-butyldimethylsilyl)-9'H-9,3':6',9''-tercarbazole (3Cz-TBS). 3, 6-dibromo-9-(tert-butyldimethylsilyl)-9H-carbazole (0.88 g, 2.0 mmol), 9H-carbazole (0.74 g, 4.4 mmol), cesium carbonate (2.6 g, 8 mmol), palladium acetate (0.05 g, 0.2 mmol), tri-tert-butylphosphine (10% in Toluene, 1.4 mL) and toluene (40 mL) were added to a two-necked flask (100 mL) under nitrogen atmosphere. The mixture was stirring at 110 °C for 12h. After cooling to room temperature, the reaction was filtered and purified by column chromatography to give a pale-yellow product (1.06 g, 86.8%). ¹H NMR (400 MHz, DMSO-d₆) δ 8.54 (s, 2H), 8.22 (d, J = 7.7 Hz, 4H), 7.98

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(d, J = 8.8 Hz, 2H), 7.59 (d, J = 8.7 Hz, 2H), 7.38 (t, J = 7.5 Hz, 4H), 7.34 (d, J = 8.1 Hz, 4H), 7.24 (t, J = 7.3 Hz, 4H), 1.11 (s, 9H), 0.88 (s, 6H).

9'H-9,3':6',9''-tercarbazole (3Cz). 3Cz-TBS (1.06 g, 1.8 mmol), tetrabutylammonium fluoride (1 M tetrahydrofuran (THF) solution, 4 mL) and toluene (20 mL) were added to a two-necked flask (100 mL) under nitrogen atmosphere for 2 h. Then NH₄Cl (aqueous, 5.6 M, 20 mL) was added to quench reaction. The reaction mixture was extracted with CH₂Cl₂, washed with water, and further purified by column chromatography (Yield: 0.81 g of white solid, 90.3%). ¹H NMR (400 MHz, Chloroform-d) δ 11.90 (s, 1H), 8.51 (d, J = 1.7 Hz, 2H), 8.25 (d, J = 7.7 Hz, 4H), 7.85 (d, J = 8.6 Hz, 2H), 7.62 (dd, J = 8.6, 2.0 Hz, 2H), 7.47 – 7.38 (m, 4H), 7.34 (d, J = 8.1 Hz, 4H), 7.27 (t, J = 7.3 Hz, 4H).

9'-(4-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenoxy)phenyl)-9'H-9,3':6',9''-tercarba zole (3Cz-o-TRz). TRz-o-PhBr (0.48 g, 1.0 mmol), 3Cz (0.54 g, 1.1 mmol), cesium carbonate (0.65 g, 2 mmol), palladium acetate (0.02 g, 0.05 mmol), tri-tert-butylphosphine (10% in Toluene, 0.8 mL) and toluene (30 mL) were added to a two-necked flask (100 mL) under nitrogen atmosphere. The mixture was stirring at 110 °C for 12h. After cooling to room temperature, the reaction was filtered and purified by column chromatography to give a white product (0.54 g, 60.2%). ¹H NMR (400 MHz, Chloroform-d) δ 8.88 (d, J = 8.8 Hz, 1H), 8.79 (dd, J = 8.0, 1.5 Hz, 2H), 8.29 (d, J = 1.6 Hz, 1H), 8.17 (d, J = 7.7 Hz, 2H), 7.76 (d, J = 8.8 Hz, 1H), 7.71 – 7.55 (m, 5H), 7.48 – 7.37 (m, 5H), 7.35 (d, J = 8.8 Hz, 1H), 7.31 – 7.27 (m, 2H). ¹³C NMR (100 MHz, Chloroform-d) δ 171.66, 170.92, 160.66, 156.31, 141.80, 140.90, 136.24,

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132.70, 132.56, 131.86, 131.21, 130.48, 128.96, 128.67, 126.35, 125.91, 123.95, 123.20, 120.88, 120.32, 119.80, 119.73, 118.77, 111.23, 109.69. MS (EI). Calcd for C63H40N6O ([M]⁺): m/z 897.05. Found: m/z 897.10.

Table S1. Summary of photophysical parameters for six exciplex emitters.

a)The photoluminescence of 3Cz-o-TRz-based blend films; ^b)The total photoluminescence quantum yield; ^c)The prompt fluorescence quantum efficiency;^d)The delayed fluorescence quantum efficiency; ^e)The prompt fluorescence lifetime; ^f)The delayed fluorescence lifetime.

Figure S1. The molecular structures of the materials used in this work.

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100 200 300 400 500 600 20

30 40 50 60 70 80 90 100 110

0 100 200 300

Temperature (℃)

Residual weight(%)

Temperature (℃) T_d= 508℃

Figure S2. TGA and DSC of 3Cz-o-TRz

-2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0

Current(a.u.)

Potential(V)

Figure S3. Cyclic voltammograms of 3Cz-o-TRz

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Figure S4. The energy level diagrams of constituent materials of 3Cz-o-TRz-based exciplexes

2 3 4 5 6 7

0 50 100 150 200 250 300 a)

Current Density(mA·cm-2)

Voltage(V)

TAPC: 3Cz-o-TRZ TPA-PXZ: 3Cz-o-TRZ m-MTDATA: 3Cz-o-TRZ

10⁰ 10¹ 10² 10³ 10⁴

Luminance(cd·m-2)

1 10 100 1000 10000

1 10 100 b)

Current Efficiency (cd/A)

Luminance (cd·m^-2)

TAPC: 3Cz-o-TRZ TPA-PXZ: 3Cz-o-TRZ m-MTDATA: 3Cz-o-TRZ

Figure S5. a) Current density-Luminance-voltage characteristics, b) Current efficiency–luminance plots of Donors: 3Cz-o-TRz

2 3 4 5 6 7 8 9 10

0 50 100 150 200 a)

Current Density(mA·cm-2)

Voltage(V)

3Cz-o-TRZ: B3PyMPM 3Cz-o-TRZ: B4PyMPM 3Cz-o-TRZ: PO-T2T

10⁰ 10¹ 10² 10³ 10⁴

Luminance(cd·m-2)

1 10 100 1000 10000

1 10 100 b)

Current Efficiency (cd/A)

Luminance (cd·m^-2)

3Cz-o-TRZ: B3PYMPM 3Cz-o-TRZ: B4PYMPM 3Cz-o-TRZ: PO-T2T

Figure S6. a) Current density-Luminance-voltage characteristics, b) Current efficiency–luminance plots of 3Cz-o-TRz: Acceptors

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Figure S7. Schematic of the carrier injection and transporting mechanism of the tandem OLED

Figure S8. ¹H NMR of TRz-o-PhBr (400 MHz, CDCl3)

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Figure S9. ¹H NMR of 3Cz-TBS (400 MHz, DMSO-d6)

Figure S10. ¹H NMR of 3Cz (400 MHz, CDCl3)

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Figure S11. ¹H NMR of 3Cz-o-TRz (400 MHz, CDCl3)

Figure S12. ¹³C NMR of 3Cz-o-TRz (400 MHz, CDCl3)