LIU ET AL.
3
extracted organic solution. A rotary evaporator was used to concen-
trate the solvent. The crude product was used for column chromatog-
raphy PE:CH2Cl2 = 15:1, PE:CH2Cl2 = 13:1, PE:CH2Cl2 = 10:1;
500 ml was purified as the eluent, and 3,5-bis(30,50-dimethylphenyl)-
benzaldehyde with a yield of 89.4% (1.87 g) was obtained. 1H-NMR
(400 MHZ, CDCl3) δ 10.17 (s, 1H), 8.07 (s, 3H), 7.33 (s, 4H), 7.10 (s,
2H), 2.42 (s, 12H). 13C-NMR (101 MHz, CDCl3) δ 192.49, 142.88,
139.79, 138.61, 137.29, 131.85, 129.71, 127.05, 125.15, 21.43.
2.59 (s, 6H), 1.55 (s, 6H), 1.39 (s, 36H). 13C-NMR (101 MHz, CDCl3) δ
164.60, 162.16, 156.32, 142.86, 140.96, 139.97, 136.75, 131.00,
126.06, 121.63, 110.21, 109.95, 103.84, 103.19, 14.67. 19F-NMR
(376 MHz, CDCl3) δ ꢀ146.17 (q, JB, F = 67.68 Hz). HRMS (ESI) m/z
+
calcd for
C
47H59BFN2 [M + H]+ 681.4749, found 681.4751
(Figure S3).
2.2.7
|
Compound 1d
2.2.4
|
Compound 1a
A red solid was obtained, yielding 63%. 1H-NMR (400 MHZ, CDCl3) δ
7.84 (s, 1H), 7.56 (d, J = 4.0, 2H), 7.15 (dd, J = 8.0, 4H), 6.84–6.89 (m,
J = 4.0, 2H), 6.03 (s, 2H), 2.58 (s, 6H), 1.48 (s, 6H). 13C-NMR
(101 MHz, CDCl3) δ 155.57, 151.64, 143.56, 143.29, 141.77, 139.47,
135.75, 131.51, 126.86, 125.22, 122.29, 121.41, 121.33, 35.07,
In total, 1.29 g 2,4-dimethylpyrrole and 1.7 g 3,5-bis(30,50-
dimethylphenyl)-benzaldehyde were dissolved in anhydrous CH2Cl2
(100 ml) in a N2 atmosphere. Eight drops of trifluoroacetic acid (TFA)
were added to the reaction, and the mixture was stirred overnight.
After the reaction was completed through TLC, 1.35 g 2,3-dichloro-
5,6-dicyano-1,4-benzoquinone (DDQ) were mixed with redistilled dic-
hloromethane and added to the reaction, which continued for 12 h.
Triethylamine (10 ml) was added to the reaction mixture and stirred
for 15 min, BF3ꢂEt2O (10 ml) was added. The reaction mixture was
stirred for another 5 h, the mixture was washed several times with
water and then extracted with CH2Cl2. The organic phase was dried
over anhydrous sodium sulfate, the coarse product was purified by
column chromatography using PE:CH2Cl2 = 6:1, and 2.5 L was puri-
31.53, 14.79. 19F-NMR (376 MHz, CDCl3)
δ
ꢀ146.22 (q, JB,
+
F = 67.68 Hz), ꢀ108.61 (s). HRMS (ESI) m/z calcd for C31H23BF5N2
[M + H]+ 529.1869, found 529.1865 (Figure S4).
2.2.8
|
Compound 1e
A red solid was obtained, yielding 62%. 1H-NMR (400 MHZ, CDCl3) δ
8.06 (s, 4H), 7.96 (s, 2H), 7.93 (s, 1H), 7.70 (s, 2H), 6.06 (s, 2H), 2.59 (s,
6H), 1.51 (s, 6H). 13C-NMR (101 MHz, CDCl3) δ 156.59, 142.47,
141.48, 140.63, 139.08, 137.66, 133.25, 132.92, 132.59, 132.19,
131.18, 127.48, 127.25, 126.46, 124.49, 122.15, 121.82,
46.67, 15.03, 14.67, 8.72. 19F-NMR (376 MHz, CDCl3) δ ꢀ146.20
fied as an eluent.
A
difluoro-boron compound of 3,5-bis(30,50-
dimethylphenyl)-phenyl (1a) was obtained as a red powder with a
yield of 58% (986 mg). 1H-NMR (400 MHZ, CDCl3): δ 7.91 (s, 1H),
7.51 (s, 2H), 7.04 (s, 2H), 6.01 (s, 2H), 2.57 (s, 6H), 2.39 (s, 12H), 1.52
(s, 6H). 13C-NMR (101 MHz, CDCl3) δ 155.58, 143.15, 142.81,
141.66, 140.09, 138.61, 135.74, 131.45, 129.58, 126.20, 124.95,
121.26, 21.42, 14.79. 19F-NMR (376 MHz, CDCl3) δ ꢀ146.22 (q, JB,
(q, JB,
= 63.92 Hz), ꢀ62.66 (s). HRMS (ESI) m/z calcd for
F
C
35H24BF14N2+ [M + H]+ 749.1803, found 749.1808 (Figure S5).
F = 67.68 Hz). HRMS (ESI): m/z calcd for C35H35BF2N2 [M + H]+
2.3
|
DFT calculations
+
533.2961, found 533.2997 (Figure S1).
Molecular calculations were implemented in the Gaussian 09 pro-
gram.[28,29] The ground states of the compounds 1a–1e were fully
optimized by a functional (B3LYP) and basis set 6-31G*.
2.2.5
|
Compound 1b
A red solid was obtained, yielding 69% 1H-NMR (400 MHZ, CDCl3) δ
7.90 (s, 1H), 7.52 (d, J = 4.0, 2H), 6.77 (d, J = 4.0, 4H), 6.51 (t, J = 4.0,
2H), 6.01 (s, 1H), 3.86 (s, 12H), 2.58 (s, 6H), 1.51 (s, 6H). 13C-NMR
(101 MHz, CDCl3) δ 161.31, 155.87, 143.07, 142.52, 142.00, 141.29,
135.77, 131.16, 126.37, 125.93, 121.70, 105.35, 99.59, 55.55, 14.86.
19F-NMR (376 MHz, CDCl3) δ ꢀ146.23 (q, JB, F = 60.16 Hz). HRMS
2.4
|
Fabrication of blue-driven LEDs
The chip emits a blue light at around 470 nm. The filling ratio (C:com-
pound) of the compound in the glue is A:B:C = 100:10:40 (mg). The
mixture was stirred in the same direction, and air bubbles were
removed by vacuum for 15 min, and the mixture then deposited on
the LED chip. Electroluminescence spectra of the LEDs were
implemented at 125.9ꢁC using an Everfine HAAS-2000 instrument,
the LED with a forward current range from 300 to 350 mA. To gather
light, the LED was placed in an integrating sphere with a diameter of
30 cm, and coupled to a high-precision array with a spectroradiometer
(wavelength accuracy < 0.3 nm) and a programmable test power
supply LED 300.
(ESI) m/z calcd for C35H35BFN2O4 [M + H]+ 577.2674, found
+
577.2624 (Figure S2).
2.2.6
|
Compound 1c
An orange solid was obtained, yielding 65%. 1H-NMR (400 MHZ,
CDCl3) δ 7.97 (s, 1H), 7.53 (d, J = 4.0, 2H), 7.51 (s, 6H), 6.02 (s, 2H),